Method and catheter for creating an interatrial aperture

ABSTRACT

A catheter device 10 with a cutting structure or means 16 on the distal portion 14 is disclosed, along with a medical procedure for using the device. The catheter 10 is configured in such a way as to create a permanent interatrial aperture in the heart, including creating a permanent interatrial hole and/or removing tissue.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. patentapplication Ser. No. 16/149,638, filed Oct. 2, 2018, which claimspriority to U.S. patent application Ser. No. 15/089,547, filed Apr. 2,2016, which claims priority to U.S. patent application Ser. No.14/738,802, filed Jun. 12, 2015, now U.S. Pat. No. 9,814,483, whichclaims priority to U.S. Provisional Application No. 62/012,212 filedJun. 13, 2014, the entire disclosures of which are hereby incorporatedby reference.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to medical devices and methods of medicaltreatment. The invention relates to a medical device and method oftreatment used to create an aperture in the interatrial septum of aheart.

Background Art

There are some medical conditions that are treated by creating anopening between body chambers in order to create a connection betweenthe chambers. The heart has an interatrial septum or wall that separatesthe left atrium and the right atrium. In certain heart failure patients(e.g., heart failure with preserved ejection fraction (diastolicdysfunction)) there is a need to allow blood flow from the left atriumto the right atrium to reduce left atrial pressure. Likewise, certainother heart diseases and conditions, such as congenital heart diseasesand pulmonary hypertension may be treated by making an interatrialopening; however, the goal is to create a right-to-left shunt to reducethe high right-sided pressure.

One procedure uses a balloon to create a hole in the septum. However, ithas been found that a hole created in this manner may not stay open andafter a period of time may spontaneously close. This renders thisparticular therapeutic solution temporary.

A few other devices have been proposed in order to overcome thetemporary solution of using a balloon. Implanting a stent in theinteratrial septum has been used as a treatment for elevated pressure inone atrium by allowing blood to flow through the opening to the otheratrium to reduce atrial pressure. A heart surgeon implants the stents incertain predetermined sizes in an effort to control the amount of bloodflow between the atria. Thus, one device is to use a stent to keep thehole open. Another device uses a valve inserted into the septum thatkeeps the hole open and also assists in controlling blood flow.Significant drawbacks to these devices are that they are permanentimplants that can promote thrombosis and are potentially subject toinfection.

Another major drawback of these devices is that they are not capable ofremoving a segment of the septum. The benefit of removing a segment ofthe septum is that aperture will be less likely to close spontaneously.The stents may also become spontaneously dislodged and embolize andcause cardiac damage or blockage of blood flow.

Therefore, it would be desirable to have a medical device that iscapable of creating an incision or an opening in the interatrial septumof the heart to alleviate pressure between chambers in the heart thatdoes not suffer from the limitations of prior devices or procedures. Itwould be advantageous to have a catheter that can create various slits,openings, or apertures in the interatrial septum in a predeterminedorientation. It would also be advantageous to have a catheter that maybe easily manipulated to remove a section of the interatrial septum toform a permanent aperture that is less likely to spontaneously close.

BRIEF SUMMARY OF THE INVENTION

The present invention solves these needs by providing a medical devicethat creates a hole in the interatrial septum and/or removes tissue asneeded. In one embodiment a medical device assembly includes a sheaththat includes an elongated shaft with a first bend region, a centrallumen, a distal end with a distal end lumen and a first steering wire,the steering wire having a first position and a second position, whereinat the first position the first bend region is substantially linear, andwherein at the second position the distal end and the distal end lumenof the sheath are substantially perpendicular to an inter atrial septum.The assembly may also include a catheter inside the sheath, the catheterincluding a shaft having a central lumen. The assembly also includes ashaped blade that includes a blade cutting edge that is oriented at asubstantially right angle to the longitudinal axis of the sheath whenthe sheath is oriented substantially perpendicular to the inter atrialseptum, and is adapted to cut a 3 mm or larger durable aperture in theinteratrial septum, a tissue articulator having a first setting and asecond setting, the tissue articulator being adapted to hold theinteratrial septum against the shaped blade for cutting while in thesecond setting, and an actuator operably connected to the tissuearticulator, the actuator having a first position and a second position,wherein when the actuator is in the second position the tissuearticulator holds the interatrial septum against the shaped blade.

In another embodiment the assembly includes a marker to identify thecatheter location on a visualization system. In another embodiment thearticulator is a suction device.

In one embodiment the assembly does not cross the interatrial septum. Inparticular, while a tissue grabbing element may retain the tissue orenter it, such as a hook, no element such as a guidewire or needlecrosses the septum. In another embodiment the articulator is adapted toretain the interatrial septum from only the same side of the interatrialseptum as the shaped blade cuts the interatrial septum. The shaped bladecan be a circular blade, a square blade, a triangular blade, asawtoothed blade, a franseen blade, or a polygonal blade.

In another embodiment the assembly also includes a tissue removaldevice. The articulator can be the tissue removal device. The tissueremoval device can be adapted to remove or hold a first tissue portionso that the articulator can hold a second tissue portion against theblade and make a second cut on that second tissue portion. In anotherembodiment the tissue removal device is a vacuum that removes the firsttissue portion.

In one embodiment the assembly further includes an anchor. The anchorcan attach to a tissue, such as for example the interatrial septum.Alternatively, the anchor can attach to the patient's exterior or thepatient's bedside. In another embodiment a robotic system provides theanchoring mechanism by securely holding the catheter or handle. Inanother embodiment the assembly further includes an orthogonal guide,the orthogonal guide adapted to hold the shaped blade in an orthogonalposition to the interatrial septum.

In another embodiment the medical device assembly includes a sheath thatincludes an elongated shaft with a first bend region with a firstpreshaped bend, a central lumen and a distal end with a distal endlumen. The first preshaped bend is adapted to position the distal endand the distal end lumen of the sheath substantially perpendicular to aninter atrial septum. The device further includes a catheter inside thesheath. The catheter includes a shaft with a central lumen, a shapedblade that includes a blade cutting edge that is oriented at asubstantially right angle to the longitudinal axis of the sheath whenthe sheath is oriented substantially perpendicular to the inter atrialseptum, and is adapted to cut a 3 mm or larger durable aperture in theinteratrial septum. The assembly also includes a tissue articulator witha first setting and a second setting, the tissue articulator beingadapted to hold the interatrial septum against the shaped blade forcutting while in the second setting. The assembly may also include anactuator connected to the tissue articulator, the actuator having afirst position and a second position, wherein when the actuator is inthe second position the tissue articulator holds the interatrial septumagainst the shaped blade.

In another embodiment the assembly includes a suction opening configuredto provide suction in the approximate area of the shaped blade. Inanother embodiment the tissue articulator is a tapered cone having aproximal face, the proximal face being adapted to retain a tissue.

In another embodiment a method of treating a heart is disclosed. Themethod includes the steps of inserting a catheter into the right atriumof the heart. In one embodiment the catheter includes a shaft, a distalcatheter lumen, a shaped cutting blade arranged around the distalcatheter lumen, a tissue articulator, the tissue articulator having afirst position and a second position, an actuator connected to thetissue articulator, and a steering mechanism. In one embodiment thecatheter acts entirely from the right atrium. Thus, while the catheteris in the right atrium, the physician actuates the actuator to move thetissue articulator into a second position that holds the tissue againstthe shaped cutting blade, cuts an aperture in the interatrial septumbetween the right atrium and the left atrium, and removes a cut tissuefrom the right atrium.

In another embodiment, the method further includes the step of attachinga tissue removal device to a portion of the interatrial septum. Inanother embodiment the method further includes the step of pulling theattached tissue into a lumen at a distal end of the catheter shaft usingsuction.

In one embodiment, the medical device includes a catheter with acatheter shaft that has a central lumen and a distal catheter lumen. Thecatheter also has a shaped blade around the distal catheter lumen. Theblade is adapted to cut an area of tissue to create an aperture in atissue. The catheter also has a tissue articulator, the tissuearticulator having a first position and a second position, is configuredto move with respect to the shaped blade, and is adapted to hold thetissue against the shaped blade for cutting while in the secondposition. The catheter also includes an actuator connected to the tissuearticulator, the actuator having a first position and a second position,wherein when the actuator is in the second position the tissuearticulator holds the tissue against the shaped blade.

In another embodiment the medical device of includes a sheath adapted toprotect tissue from the shaped blade before the shaped blade isdeployed. The shaped blade may be a circular blade, a square blade, atriangular blade, or a polygonal blade. Likewise, the blade can providean elongated slit with a small width and a radius on each end—to createa structure that has a small sectional area under low pressure, butincreases in area with a high pressure differential. In anotherembodiment the medical device includes a tissue removal device. Thetissue removal device may include a hook, a balloon, or an expandablebasket. In one embodiment the distal catheter lumen is larger than thecentral catheter lumen.

In one embodiment the medical device includes multiple blades on theexterior of the catheter shaft. The blades can be arranged apart fromeach other circumferentially around the catheter shaft and extendingoutward from the catheter shaft. Each blade may be attached to thecatheter shaft by, for example, a pin and be adapted to expand away fromthe catheter shaft when actuated, e.g., by moving an actuator.

The medical device may include a first radiopaque marker on the distalend of the catheter. It may also, or in the alternative, include anultrasound marker on the distal end of the catheter.

The medical device in one embodiment includes a sheath. The sheath mayalso have a radiopaque marker on the distal end of the sheath. Theradiopaque markers may be the same or different and may be configured toidentify when the catheter has exited the sheath.

In another embodiment the medical device further includes a suctionopening configured to provide suction in the approximate area of thecutting blade.

The tissue articulator can be a tapered cone having a proximal face, theproximal face being adapted to retain a tissue, and may be adapted tofit within the distal lumen of the catheter shaft.

In another embodiment, the medical device includes a tenting deviceadapted to tent a target tissue into the distal lumen of the cathetersuch that a larger portion of the target tissue may be cut by thecutting device.

In one embodiment the shaped blade is formed of a memory metal, thememory metal being biased to expand when removed from the catheter orthe sheath to provide a cutting surface substantially larger than thediameter of the catheter.

In another embodiment the medical device includes a catheter with acatheter handle, a catheter shaft, the catheter shaft having a centrallumen and a distal catheter lumen, a circular blade around the distalcatheter lumen, a tissue removal device, a guidewire adapted to passthrough the central catheter lumen, and includes a sheath adapted toprotect tissue from the circular blade before the circular blade isdeployed

In another embodiment the invention is a method of treating congestiveheart failure including the steps of inserting a catheter into the rightatrium of the heart, the catheter including a shaft, a distal catheterlumen, a shaped cutting blade arranged around the distal catheter lumen,a tissue articulator, the tissue articulator having a first position anda second position, an actuator connected to the tissue articulator. Theembodiment further includes the steps of crossing the interatrialseptum, actuating the actuator to move the tissue articulator into asecond position that holds the tissue against the shaped cutting blade,cutting an aperture in the interatrial septum between the right atriumand the left atrium, removing a cut tissue from the right atrium.

In one embodiment the method further includes a step of attaching atissue removal device to the interatrial septum. In another the methodfurther includes a step of pulling the attached tissue into a lumen at adistal end of the catheter shaft. The method may also include a step ofexpanding the cutting device to a diameter greater than the diameter ofthe catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial perspective view of a catheter constructed accordingto the present disclosure;

FIG. 1A is a partial perspective view of a catheter and a retentionmechanism inserted into a target tissue;

FIG. 2 is a partial perspective view of a catheter constructed accordingto the present disclosure;

FIG. 3 is a partial perspective view of a catheter constructed accordingto the present disclosure;

FIG. 3a is a cross sectional view of the catheter of FIG. 3 taken alongline 3A on FIG. 3;

FIG. 3B is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 4 is a partial perspective view of a catheter constructed accordingto the present disclosure;

FIG. 5 is a cutaway partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 6 is a partial perspective view of a catheter constructed accordingto the present disclosure;

FIG. 7 is a partial perspective view of a catheter constructed accordingto the present disclosure;

FIG. 8 is a partial perspective view of a catheter constructed accordingto the present disclosure;

FIG. 8A is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 9A is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 9B is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 9C is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 9D is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 10A is a partial perspective view of a cutter constructed accordingto the present disclosure;

FIG. 10B is a partial perspective view of a cutter constructed accordingto the present disclosure;

FIG. 10C is a partial perspective view of a cutter constructed accordingto the present disclosure;

FIG. 10D is a partial perspective view of a cutter constructed accordingto the present disclosure;

FIG. 11A is a partial perspective view of a catheter handle constructedaccording to the present disclosure;

FIG. 11B is a partial perspective view of a catheter handle constructedaccording to the present disclosure;

FIG. 11C is a partial perspective view of a catheter handle constructedaccording to the present disclosure;

FIG. 12A is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 12B is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 12C is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 12D is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 12E is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 12F is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 12G is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 12H is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 12I is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 13 is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 14A is a cross sectional view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 14B is a cross sectional view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 15A is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 15B is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 16A is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 16B is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 16C is a partial perspective view of a catheter constructedaccording to the present disclosure;

FIG. 16D is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure;

FIG. 17A is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure making a second cut;

FIG. 17B is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure making a second cut;

FIG. 18 is a partial perspective view of the distal end of a catheterconstructed according to the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In general, the invention comprises a medical procedure andcorresponding medical devices for therapeutic surgical procedures. Inparticular, the invention comprises a method of creating an aperturebetween heart chambers for blood flow and devices for creating thataperture. In this context, an aperture is a created space or gap largeenough to allow significant blood flow between the two chambers itconnects, to treat or improve heart failure, pulmonary hypertension, orsimilar diseases, without the use of an implanted device.

In order to treat congestive heart failure, it must first be diagnosed.In particular diagnosis may comprise listening to the lungs for signs ofcongestion, measurement of vital signs, a chest x-ray of the lungs,electrocardiogram (ECG), an echocardiography and other imagingmodalities to assess cardiac output, ventricular contraction andfilling, atrial size, and cardiac valve function, etc., insertion of acentral venous catheter and measurement of pulmonary capillary wedgepressure (PCWP), a blood tests, e.g., to check for chemicals such asbrain natriuretic peptide (BNP and N-terminal pro-B-type natriureticpeptide (NT-proBNP), a stress test, cardiac catheterization and/or anMRI or CT scan. In addition, transthoracic echocardiography (TTE) ortranseophogeal echocardiography (TEE) may be used to confirm the absenceof any current holes between the chambers of the heart.

Once congestive heart failure is diagnosed a course of treatment will bedesigned. While it is possible to treat congestive heart failure withsurgery, implants, or other methods, herein disclosed is a method ofadvantageously treating congestive heart failure without surgery andwithout leaving behind an implant.

The disclosed procedure preferably begins with a percutaneous entry intoa vein, preferably the femoral vein in the groin region. It is alsopossible to gain entry via a jugular or subclavian vein or neck vein.Typically a sheath with a guide wire is inserted through thepercutaneous entry and maneuvered by the physician to the right atrialchamber. The sheath used in the present invention may be steerable, forexample controlled by pull wires which extend from its distal region toa handle at its proximal end, the handle having one or more actuators.Likewise the sheath may be pre-curved or pre-bent such that it willautomatically orient towards the interatrial septum once it reaches theright atrium.

Once in the right atrium, the physician will identify the portion of theinteratrial septum at which he will create the interatrial aperture.Typically, this will be at the fossa ovalis. Because the fossa ovalis isthinner than the remainder of the interatrial septum, it will be easiestto cut an aperture at its location. To identify the fossa ovalis thephysician may employ one or more means of tissue thickness sensing. Forexample the physician may use an electrode and test for impedancechanges, may employ one or more ultrasound methods, or may simply testfor tenting. For example, the physician may apply a small amount ofpressure to the interatrial septum and search for tenting in the tissue.Once the physician locates the spot where the tissue easily tents, e.g.the fossa ovalis, the physician will deploy the present device to createthe aperture. In some embodiments it is desirable to cross into the leftatrium. As such, the physician will create a small puncture in theseptum using a transseptal device. For example a brockenbrough needle, aBRK needle, or another transseptal device may be used for crossing theseptum into the left atrium. Once there, the guidewire is threadedthrough the interatrial septum puncture and the distal end of theguidewire is left in the left atrium. The proximal end of the guidewirewill remain outside of the body, with its entry point at the femoralvein. As with the sheath, the guidewires described herein may bepre-curved or pre-bent such that they will automatically orient towardsthe interatrial septum once reaching the right atrium.

Depending on the therapeutic catheter that will be used in the latterportion of this procedure it is possible that a guidewire may not berequired, and in some cases that the device may not cross into the leftatrium at all. In such instances a transseptal device may not benecessary either. If the catheter to be used to form the interatrialaperture is designed to create its own transseptal crossing or create anaperture without crossing the septum, the guidewire or transseptaldevice may be avoided, potentially saving cost and time.

With the guidewire in place, the sheath may be removed. If so, asurgical catheter and/or a sheath will be provided and directed over theguidewire into the right atrium. Once there the therapy catheter,further to the surgical mechanisms disclosed in detail below, willcreate a durable interatrial aperture.

During the procedure the physician will monitor the location of thecatheter and/or sheath as well as the progress of the cut, the nature ofthe aperture, or other procedure details via fluoroscopy, MRI,ultrasound, or transesophageal echocardiography, intracardiacechocardiography (ICE) or similar tracking or visualization technologyfor guidance. Toward this end, it is preferred that the catheterincludes radiopaque or ultrasound markers as described in further detailbelow. Likewise, the physician may monitor the location of the catheterand/or sheath as well as the progress of the cut, the nature of theaperture, or other procedure details via a camera, such as a CCD camera.In the latter case it may be advantageous to apply a hood over theoperation region, empty the hood of blood and replace it with saline,such that the procedure may be visually monitored. This hood may also beused, as discussed in detail below, to provide an orthogonal orientationto the cutting blade and the target tissue. Other location systems arepossible, including MRI, electroanatomical navigation systems such asEnSite®, Carto®, or MediGuide® systems, along with the correspondingsensors on the introducer 50 and catheter 10.

The interatrial aperture will be created by one of two mechanisms or acombination thereof. First the surgical catheter will create anaperture. The catheter could use a cutting blade or other meansdisclosed herein to create an aperture or cut pattern in the interatrialseptum such that a sufficient flow of blood may occur between the twoatria. For example, the catheter may cut an X-pattern aperture in theseptum. Doing so leaves flaps that will open and close depending on thepressure differential between the two atria. Likewise the catheter maycreate a circular or semi-circular hole in the septum. Such openings mayhave benefit in determining the direction of blood flow in order tomaximize left-to-right and minimize right to left flow especially inpatients with combined left and right heart failure as occurs inpatients with HFrEF. Similarly, an elongated hole such as a 1 mm wideslit with radiused ends may have low csa and shunting with low pressuredifferential and increased csa and shunting with higher pressuredifferential. The utility of such a design may have particular valuewith HFrEF patients.

Second the catheter may remove tissue. For example in creating a shapedaperture the catheter may utilize a cutting blade to cut the tissue fromthe septum and remove it from the body. Loose tissue removal is criticalso that any loose tissue does not remain in the atria, creating asubstantial risk of stroke due to embolization.

In either mechanism, the physician preferably engages the target tissuewith a distal portion of the device, such as a tissue articulator. Thetissue articulator may penetrate into or through the tissue, and then beactuated (e.g., via an actuator on the catheter or sheath handle) tohold the tissue against the cutting blade. Alternatively, thearticulator may hold the tissue and the blade may approach it forcutting the tissue. Thus, the articulator works with the blade for oneor more purposes, it may hold the tissue in place, guide the blade tothe desired portion of the tissue, hold the catheter in place and ontarget, retain any loose tissue, or create an initial opening in thetissue for the device to pass into.

In a preferred embodiment, the tissue articulator passes through thetissue as the catheter or sheath is advanced. Alternatively, anactuator, (e.g., an actuator on a handle, or simply a movablelumen/guide within the medical device) may be in or moved to a firstposition that advances or locates the tissue articulator forward awayfrom the cutting blade. This advancement (or a separate advancement) maypush the tissue articulator through the tissue. Once the tissuearticulator is in place, either by actuation or mere advancement, theactuator is activated to a second position that causes the articulatoror blade to engage the tissue. The second position (or a third position)may also pull the tissue into a lumen in the catheter or sheath, tentingit so that a larger aperture may be cut.

For proper utility in patients who need transeptal shunting of blood itis critical that the aperture be “durable” such that it will stay openfor a long period of time and even permanently, as defined below. Theshunt size can be titrated by measuring the left atrial pressure eitherat rest or with exercise. Likewise, the doctor can measure oxygensaturation in the right atrium, or cardiac output. The medical device ofthe present invention preferably includes means to measure pressureand/or oxygen saturation, such as a sensor or via fluid removal fortesting.

In one version of the procedure, the device crosses the septum into theleft atrium and records the resting pressure (or with exercise). AT thispoint the durable aperture is cut. Then, the pressure measurement isagain performed and it is determined if the aperture is sufficient. Oneadvantage of the present procedure and device is the ability to measuresuccess during the procedure, and adjust the shunt size as needed,rather than waiting until post procedure and having to reenter thepatient.

In certain patients it is preferred that the hole be at least 3 to 12mm, preferably 4 to 10 mm, or 6 to 8 mm, in diameter for the desiredclinical benefit. In other patients a higher pressure may indicate thata smaller aperture be formed, e.g., 0.5 to 5 mm, or 2-3 mm. However,such small hole sizes have increased risks of closing, tissue healing,and plugging, and are accordingly unlikely to be durable absentexceptional circumstances. The interatrial shunt lowers LA pressureespecially during exercise in heat failure patients. The left-to-rightshunting can cause a decrease in left ventricular (LV) CO and anincrease in right ventricular CO. The reduction in LA pressure, however,might allow patients to achieve a higher level of exertion leading tohigher heart rate and thus an increase in LV CO. Furthermore, increasesin RA pressure and pulmonary arterial pressure can occur, but in HFpatients, despite the increase in RV CO, a reduction in pulmonary venouspressure can actually occur. The size of the shunt can determine theextent of all these hemodynamic effects, and enable a Qp/Qs ratiosufficient to reduce LA pressure without RV overload. The clinicallynecessary size will vary from patient to patient. Subsequent to theprocedure the physician will monitor the patient at one month,three-month, and six-month exams to determine if the size of the holehas shrunk. While it is anticipated that healing tissue may slightlyshrink the aperture on the order of 1 to 2 mm, if the aperture remainsopen at six months it is considered “permanent” or durable for purposesherein. It is also desirable that the aperture be visible on anechocardiogram so that it can be readily measured. Ultimately, for thesepatients, safety and a proper balance of blood hemodynamics, oxygenationwill be used determine the aperture size, shape and quantity.

The tissue may be removed by a device using, for example, suction orgrasping mechanisms. In a preferred embodiment the catheter, e.g., thetissue articulator, will pull the tissue into the blade to positivelyretain it and keep it from releasing into the heart. In addition to itsutility for tissue removal, the suction and grasping mechanisms may alsobe extremely useful for positioning the device, and retaining the devicein the desired position during operation. Additionally, suction may aidin determining that the blade is orthogonal to the tissue, e.g., that ithas the proper orientation for cutting. For example, if under lightsuction in the blade's lumen a seal is formed between the blade and thetissue, the blade may be determined to be at a proper orientation to thetissue for cutting a durable aperture. Likewise, sensors on the graspingmechanism may be able to determine how far into the tissue the graspingmechanism is. If four hooks, for example, all 90 degrees apart, havepenetrated the tissue to the same depth, it may be determined that thedevice is orthogonal to the tissue.

Creating a hole in the heart without leaving behind an implant avoidsthe need for anticoagulant therapy, lowers the risk of infection, andavoids the use of an implant that may come loose over time. In additionthe procedure is substantially simpler than installing and leavingbehind an implant. Due to the lack of an implant, there are no risks ofMRI compatibility, no risk of device failure or fracture. It is easierto close the aperture if needed absent a device, and the overall totalcost of care is lower. No implant means faster and safer crossing of theseptum during future catheter based surgical procedures, such astreating atrial fibrillation or ventricular tachycardia. Finally, theprocedure is faster and will allow for a more efficient use of hospitalfacilities and physician time.

There are multiple ways to determine if the aperture is large enough tobe efficacious. Subsequent to the procedure the physician may do so by,e.g., examining the aperture on an echocardiogram visually and usingdoppler, calculating the degree of shunting, performing an exercisetolerance procedure, by measuring the ejection fraction, by measuringthe wedge pressure, oxygen saturation, or other means. It is preferredthat a clinical evaluation be conducted such as a walking test, todetermine the practical effect on the patient. The invention allows foreasier adjustment of aperture size compared to similar solutions. Inparticular, if the aperture size is too small, an additional aperturemay be created, or the existing aperture can be expanded. Becausecertain clinical evaluations can be performed immediately after thepatient is first treated, it may be possible in many cases to leave thecatheter in place during the evaluation, use the same catheter to createthe second aperture or increase the size of the existing aperture, andthereby avoid a second procedure. This determination can be performed byhaving the patient exercise using upper body exercise device andmeasuring the LA pressure prior to and during exercise. If the reductionis not sufficient to reduce PCWP then a second hole can be created andthe exercise evaluation repeated. This is not possible with the priorart devices.

Also disclosed is a medical device for creating the aperture between theleft atrial chamber and the right atrial chamber. The medical deviceshave dimensional requirements depending on several factors. First, thelength of the device will depend on its point of entry. For example, acatheter that will be used in a percutaneous entry at the femoral veinand which must reach to the right atrium will typically be at least 120cm long and more preferably 140 cm. A catheter that will enter the bodyat a different location in many cases will be substantially shorter. Themore lengthy and torturous the path the catheter must take, the stifferthe catheter body may need to be, and the more likely the catheter willbe to require stiffening elements such as a stainless steel or nitinolbraid. The need for a stiffer catheter is particularly acute for thepresent device. It must first take a long path through the body to theright atrium, then turn at a sharp angle to address the interatrialseptum, and then project enough force along that turn to push the cutterthrough the interatrial septum. It is difficult to project that forcealong the length of the catheter body, which runs from the groin regionto the heart, and then successfully get the force to take the turntoward the septum without first pushing the catheter higher inside theheart rather than to the side toward the septum. Accordingly, unlikemany prior art surgical catheters, the present device may require asubstantially stiffer body, provided by braiding, nitinol stiffeningdevices, or multiple catheter layers. Another reason for a stiffcatheter is, in combination with ridged proximal handle/end fixation(bed rail), the clinician can make fine (submillimeter) movements to thedistal tip with respect to the tissue

Typically a thinner catheter is preferred, so long as the cuttingelements are sufficiently sized to create a large enough interatrialaperture. For example, it would be preferred to have a catheter shaft ofnine French however there is always a trade-off between a small diameterdevice and the need to create a sufficiently sized interatrial aperture.Thus it may be advantageous to have a small diameter shaft for the bulkof the catheter length combined with a somewhat larger distal workingend on the catheter or an expandable distal working end that has a smalldiameter upon insertion to the vein and can be expanded once in theright atrium and then collapse back to a smaller diameter for removalthrough the vein. On the proximal end of the catheter it is advantageousto have an easily manipulable handle so that the physician can directthe catheter into its desired location and control the cutting device.

With reference to FIG. 1, the catheter 10 comprises an elongatedcatheter shaft 12 having a distal end 14 and a proximal end 15. Proximalend 15 includes a handle 18. The handle 18 comprises a first actuator 20and a second actuator 22. Handle 18 further includes a fluid port 24 andan electrical connection (not shown). Catheter 10 may further includepull wires attached to an actuator for actuating distal elements, movinga lumen or shaft, steering, or the like. Catheter 10 may be pre-curvedor pre-bent such that it will automatically orient towards theinteratrial septum once it reaches the right atrium.

It may further include irrigation ports and the like. Catheter 10further includes radiopaque markers 26 in a designed pattern that allowsthe physician to determine the location and orientation of the catheter10 in the patient and the orientation of the different components of thedevice relatively to each other. Catheter 10 may further includeultrasound markers 28 again in a designed pattern such that thephysician may locate the catheter 10 in the patient on ultrasoundimaging.

The elongated catheter shaft 12 is preferably hollow, having a lumen 13that has the ability to pass a guidewire 40 through it. Catheter 10 isdesigned to work in conjunction with an introducer 50. Introducer 50 mayeither extend the entire length from the percutaneous incision to theleft atrium of the heart, or may only cover a portion of catheter 10.

The distal end 14 of catheter 10 comprises a cutting means 16. In afirst embodiment the cutting means 16 is a razor like member formed ofsteel or another suitable metal or material adapted to cut a thintissue. Toward this end the cutting means may be very thin so that itcleanly and easily pierces the thin tissue. In those embodiments wherecutting means 16 has a sharp edge exposed at the end of the catheter 10,it is it is preferred that the introducer 50 cover and protect the veinand other tissue from the cutting means 16 until the catheter 10 isdelivered in place and actuated by the physician to cut the targettissue. In other embodiments a cone (not pictured) or other distalelement may cover or sit flush with the cutting blade 16 so that theblade is protected until actuation.

The cutting means 16 may be a serrated blade which will allow for alower cutting force. Likewise the cutting means 16 may comprise avibrating blade to likewise allow for a lower cutting force.

The introducer 50 is typically a hollow sheath. Introducer 50 mayinclude braiding along the outer cylinder to provide stiffening.Introducer 50 may further include a handle at the proximal end, anactuator, and pull wires attached to the actuator for steering,irrigation ports and the like. In particular, pull wires may be stronglyadvantageous. Unlike prior art devices which create a hole by energysources or by implanting a device, the present device may find thatsignificant pressure on the cutting blade 16 is necessary. Accordingly,in a preferred embodiment the sheath wall, and/or the catheter wall arebraided or reinforced to provide a stiffer device.

Likewise, because the pressure must be transmitted from the length ofthe introducer or catheter, that pressure will initially push thecutting edge and the entire catheter along rather than through theseptum. For example, in a femoral vein entry procedure, the catheter isinitially pushed upwards rather than towards the left atrium. Providingstability and steerability in either the introducer or the catheter maygreatly reduce this upward pressure and redirect the force towards theinteratrial septum 30 to provide a proper cut.

Likewise, providing anchoring means or stabilizing means can prevent thecatheter and the cutting blade from shifting and allow a clean cut inthe desired location. Thus, in one embodiment the assembly furtherincludes an anchor. The anchor can be an in vivo, such as a component atthe end of the catheter that hold the catheter in place. For example,hooks, corkscrews, or a forceps may hold the tissue tightly.Alternatively, the balloon, pigtail, or other tissue retention meansdescribed herein may serve as an anchor.

In another embodiment the anchoring mechanism is outside the body. Thus,the anchor can attach to the patient's exterior or the patient's bedsideand hold the proximal portion of the catheter securely, e.g., a handlebrace that attaches to the patient's bedside. In another embodiment arobotic system provides the anchoring mechanism by securely holding thecatheter or handle. Of course, multiple anchoring means may be employed.An anchor is important because very precise control of the catheter andthe cutting means are important for safe and successful procedures.Placing the cutting means in the wrong location or making it at thewrong angle results in a much more difficult cut, or a less safe cut asthe cutting means may perforate the atrial wall on the other side of theseptum. Thus, it is advantageous to have movement control down to the 1mm level. Of course, providing a visualization system that has a similarresolution provides a synergistic effect with having a high degree ofmovement control.

In another embodiment the assembly further includes an orthogonal guide,the orthogonal guide adapted to hold the shaped blade in an orthogonalposition to the interatrial septum.

Introducer 50 further includes radiopaque markers 26 in a designedpattern that allows the physician to determine the location andorientation of the introducer 50 in the patient. Introducer 50 mayfurther include ultrasound markers 28 again in a designed pattern suchthat the physician may locate the introducer 50 in the patient onultrasound imaging. Preferably, the radiopaque markers 26 and ultrasoundmarkers 28 on the catheter and introducer are distinguishable from eachother and accordingly the physician is able to determine which markersare on the catheter in which markers are on the introducer readily suchthat the physician is able to determine the spatial relationship of thetwo devices, the catheter 10 and the introducer 50.

This spatial relationship allows the physician is to determine when thecatheter 10 exits the introducer 50 and the cutting mechanism 16 isactive, as well as determine the location and orientations of thedevices at all times.

Ideally, in operation the introducer 50 is positioned next to or near atarget tissue 30. Specifically the introducer 50 is located near theinteratrial septum. The introducer 50 may be so located through aphysician's experience touch and feel, or using the markers 26, 28 inconjunction with imaging system. Other location systems are possible,including MRI, electroanatomical navigation systems such as EnSite®,Carto®, or MediGuide® systems, along with the corresponding sensors onthe introducer 50 and catheter 10. The sensors 26, 28, mayadvantageously be located at the tip of the sheath or the catheter. Inthis embodiment the sensors may identify on a visualization system whenthe sheath is orthogonal to the tissue 30. Likewise, electrodes,pressure sensors, fiber optics, a camera, or the like may sense thetissue contact or proximity, and may thus identify when the sheath is incontact with the tissue, and also when it is orthogonal to the tissue.In such a case it may be advantageous to have two such sensors 180degrees apart, or preferably 4 or more sensors 90 degrees apart.

While proper alignment of the catheter or sheath is discussed above, andis important in most embodiments, it is understood that in thoseembodiments the alignment of the sheath with the tissue is importantprimarily to align the cutter with the tissue so that the shape,location, and size of the aperture can be controlled. However, it ismost critical that the blade be aligned properly with the tissue, and income embodiments the face of the blade may not be orthogonal to thesheath or catheter. In fact, in one embodiment the blade is at a 45degree angle to the longitudinal axis of the catheter. As such, thecatheter (or sheath, guidewire) need not be bent at an orthogonal angleto the tissue, but indeed may remain straighter as the blade itself willprovide the proper orientation. Of course, the adjustment of the angleto fit the needs of the cut and the device is expected. In otherembodiments the tissue is brought into alignment with the cutter, thatis the tissue is held by the tissue retention device and turned to facethe cutter.

Once the introducer is located next to or near the target tissue 30 thecatheter 10 is advanced past the end of or to the end of the introducer50 and placed in contact with the tissue 30. Preferably using the uniquemarkers 26, 28 the physician can tell on the visualization system whenthe catheter has exited the introducer or has contacted the tissue.Likewise, the catheter 10 may include sensors (not shown) that identifywhen it contacts the tissue, such as a force sensor, fiber optics, acamera, and electrode using impedance sensing, mapping systems,ultrasound, or the like. In a first embodiment, the circular cutter 16is advanced into the tissue 30 to cut a circular aperture in the tissue.In an alternative embodiment the introducer 50 is not utilized and thecatheter itself is steered into position near tissue 30, and is advancedto cut the aperture.

In one embodiment, once the introducer is in place a transeptal crossingsystem is used to cross the fossa. Then once across the crossing systemis typically replaced with a guidewire. The guidewire 40 remains inposition across the interatrial septum and guides either the introducer50, the catheter 10, or both into position. Guidewire 40 may comprise aretention means on its distal end. Alternatively, guidewire 40 or theretention means may be a part of catheter 10. For example guidewire 40may include a balloon 42, a pigtail (not shown), an expandable nitinolbasket (not shown), a disk or expandable disk (not shown) or similarmeans. In operation the guidewire 40 is passed through the interatrialseptum. Once across, balloon 42 is inflated (or the pigtail secured orthe nitinol basket or the disk expanded) and the guidewire is pulledproximally towards catheter 10 to secure the tissue against catheter 10and cutter 16. Likewise a pigtail, hook or helical means can be utilizedto secure the tissue against catheter 10. Multiple means may be used,including a balloon 42 to push the tissue and a hook to retain any looseor dislodged tissue.

While the balloon, pigtail, or similar means are shown as being on thedistal portion of guidewire 40, they may also be on the distal portionof the catheter 10. For example a thinner, distal portion of catheter 10may be passed through the interatrial septum 30 to allow the balloon 42,or pigtail to secure the tissue 30. The distal portion of the catheterwith the articulator, e.g., balloon 42, pigtail, basket, or disk mayride over a guidewire, or may forego a guidewire entirely. In such anembodiment the catheter 10 may not need lumen 13, or may findalternative usage for it, such as irrigation or suction. Of course alumen 13 for a guidewire 40 may still use the lumen 13 for irrigationand suction as well.

In an embodiment the articulator (balloon 42, pigtail, basket, or disk)will pull the tissue of the interatrial septum into a lumen 32 ofcatheter 10 such that the tissue is tented, preferably into thecatheter's lumen (as shown). Once the tissue is tented the cutter 16will cut the tissue 30 resulting in a larger aperture due to thetenting. Tenting the tissue has several advantages. First in many casesit will allow for a larger aperture size combined with a smallercatheter size. Likewise it may give the physician a degree of controlover the size the aperture. For example if the physician desires asmaller aperture for a particular patient, he may wish to reduce theamount of tenting or keep it to a minimum. If the physician desires alarger aperture for the patient he will increase the amount of tentingpulling the tissue further into the lumen 32 creating a larger aperturewhen the cutting means 16 is applied.

While the above description describes guidewire 40 as a separate device,it is also contemplated that catheter 10 may comprise a lumen in itscenter containing the guidewire 40. In this embodiment guidewire 40 isfirst advanced across the interatrial septum, either by itself, piercingthe septum, or over a pre-existing guidewire placed earlier in theprocedure. The guidewire 40 may be actuated by the first or secondactuator 20, 22 on handle 11, manually by the physician, or by anactuator on a separate handle.

In one embodiment the handle 11 comprises a sliding actuator thatadvances the guidewire distally or withdraws it approximately in aone-to-one ratio between the movement of the guidewire and the movementof the actuator on the handle. In this situation once the catheter isadvanced to the interatrial septum and the guidewire 40 is advancedacross the septum, the balloon is inflated, and pulled back against thetissue 30 by actuation or by withdrawing the entire device. At thispoint the actuator 20 is moved proximally to pull the tissue into thecutter 16 creating the aperture in the tissue 30.

Because the guidewire may include a pigtail or hook, the tissue cut fromthe interatrial septum to complete the aperture is positively retainedthe inside the catheter 10 and is withdrawn from the body with thecatheter 10. While the guidewire has been described as having either aballoon or pigtail, other articulation and tissue retention devices arecontemplated. In particular a disc device can be utilized (not shown).The disc device may include one disc that is navigated to the distalside of tissue 30, or may include a disc on each side of the tissue 30.The two discs may be actuated to secure the tissue between them. Thedisc may be expandable having a small diameter when crossing the septumand a larger diameter when securing the tissue. Cutter 16 may ride overthe disc(s), pulling them into lumen 32 to cut the tissue which thenremains retained between the two discs and is removed from the body.

After the tissue 30 is cut the balloon 42 is deflated and it isretracted back into the catheter 10. Likewise, if the device utilizes apigtail or discs they are withdrawn into or to the catheter after thetissue is cut. Likewise catheter 10 may utilize a suction device (notshown) to remove any tissue that is cut or loosened from the atrialseptum. In one embodiment the tissue is then removed from the body whilethe catheter 10 is left in place. Accordingly, suction may be employedto remove the tissue through the lumen. Alternatively, the articulatormay be on a separate catheter (not shown) contained inside catheter 10.This separate catheter may be withdrawn with the tissue. It may then becleaned and replaced, or replaced by a second, similar device, so that asecond cut may be made safely.

The cutter 16 is preferably a shaped blade 16 located around the distalcatheter lumen 32. In a first embodiment, shaped blade 16 is circular inshape and has on its distal end a razor like member formed of steel oranother suitable metal or material. In a related embodiment the cutter16 includes saw teeth for cutting through the tissue 30. In anotherembodiment cutter 16 comprises rotary blade 16 and is capable ofspinning or rotating to cut or form an incision. The rotary blade 16 maycomprise a blade capable of spinning in relation to the catheter, or maycomprise a distal cam action on the catheter shaft. Suction or anothertissue holding mechanism is preferably employed with a rotating blade tohold the tissue in place while the cut is completed.

In other embodiments the cutter may be triangular in shape, square, oranother polygonal shape such as an octagon, such that when forcedthrough the tissue 30 the shaped blade 16 creates an aperture by cuttingout an area of the tissue creating a hole, preferably a shaped hole.Notably, the shape of the hole may not match the blade precisely, e.g.,an octagonal blade may create a circular hole, and tenting as describedherein may substantially alter the shape of the hole, e.g., a circularblade may create an oblong aperture due to uneven tenting due to manyfactors, including inconsistent tissue elasticity or thickness.Likewise, the blade can provide an elongated slit with a small width anda radius on each end—to create a structure that has a small sectionalarea under low pressure, but increases in area with a high pressuredifferential.

As shown in FIG. 1A, in another embodiment catheter 10 includes shaft12, lumen 13, distal lumen 32 cutting blade 16 as well as a tissuearticulator 60, shown in a conical shape. Tissue articulator 60 isactuatable along the lumen 13. The tissue articulator 60 may be actuatedfor one of a couple purposes, including grabbing tissue, penetratingtissue, tenting tissue, with the cutting blade 16 cutting tissue, orretaining tissue. The tissue articulator 60 may be actuated multipletimes for the same or different purposes. It may, for example, beactuated once to penetrate the septum 30. It (or the blade 16) may thenbe actuated to retain the tissue, e.g., against the blade, and thenactuated a third time for cutting.

The actuation may take one of several forms. An actuator on the handlemay be used. Likewise, the tissue articulator 60 may ride on a guidewireor a catheter that is slidable relative to catheter 10 or cutting means16. In such a case the actuator is the catheter shaft and it may be slidback and forth as needed.

The tapered cone 60 in one embodiment is the tissue articulator 60, andis attached to a stainless steel tube 61 that comprises the outerdiameter of lumen 13. The tapered cone 60 and the cutting blade 16 areboth of a sufficient diameter to cut an aperture of the desired size.For example at its widest point the tapered cone 60 may be 6 mm wide. Inoperation the tapered cone 60 rides over a guidewire 40 that runsthrough a lumen 13 to the left atrium. The tapered cone 60 is forcedthrough the atrial septum 30. As the tissue in the septum is elastic itwill stretch over the tapered cone as it passes through and then willpartially recover to fit in the space 65 between the tapered cone 60 andthe cutting blade 16. The tissue may also have some tearing present.While the space 65 may be a longer space, which may allow for moretissue to be gathered into lumen 32, in one embodiment space 65 is ashort narrow segment that only leaves enough of a longitudinal gap forthe tissue 30 to fit between the distal tip of the cutting blade 16 andthe cone 60, e.g., 2 mm. The tapered cone 60 is then actuated and pulledproximally into the lumen 32. Because the tapered cone 60 fits preciselywithin the lumen 32 it pulls into the lumen even if the catheter is atan angle or is bent. This action pulls the tissue 30 into the cuttingblade 16, cutting an aperture in the interatrial septum. The tissue 30is captured within the lumen 32 and held in place by the withdrawntapered cone 60 and removed from the body.

The tapered cone 60 may have a drug coating for one or more purposes.For example, it may have a hydrophilic coating to reduce tearing as itpasses through the interatrial septum 30. A slippery tapered cone 60will reduce tenting due to friction as it passes through the tissue.Likewise the tapered cone 60 may have a drug coating that will slowfibroblast proliferation and migration as well as the secretion ofextracellular matrices, e.g. Pacelitaxel. Likewise, the cutting blade 16may include one or more of these coatings.

As shown in FIG. 2, in another embodiment cutter 56 is formed of a shapememory metal so that when it is fully retracted and inside catheter 10it takes a more linear shape. However, when cutter 56 exits the catheterit assumes one of a number shape of shapes. For instance in a firstembodiment cutter 56 exits the catheter 10 and assumes a circular shapethat is orthogonal to catheter 10, as shown in FIG. 2. Thus when pressedagainst the tissue from the distal side (from the left atrium) thecutter 56 forms a circular loop against the tissue and cuts a circularhole. Cutter 56 may retain a straight shape while on the proximal sideof the interatrial septum, and may be forced through the septum where itassumes a circular shape on the distal side of the septum. It is pulledback against the tissue cutting the aperture. As can be appreciated,once the hole is cut, the blade 56 may be pulled back into the catheter10 and removed from the heart. The cutter 56 may include tissueretention devices as disclosed herein to retain the tissue as thecutting is performed. Likewise, suction may be employed to retain thetissue. Alternatively, the retention devices may be on the distal end ofthe catheter 10, or on the articulator. The catheter 10 may haveirrigation or suction ports 58 on the cutter 56. Cutter 56 may cut fromeither side of the tissue 30, the proximal or distal side. As may beappreciated, cutter 56 may be a shaped blade in a number of differentshapes, including a star, circle, square, triangle, or another polygon.

While in embodiments catheter 10 creates a circular aperture in theinteratrial septum, in an alternative embodiment, as shown in FIG. 3,catheter 100 is designed to create a patterned cut in tissue 30 thatwill provide a durable aperture between the two atria. In particularcatheter 100 comprises shaft 110 with a distal end 114. The distal end114 comprises blades 116. As shown in FIG. 3a , a cross-section of thedistal end of the catheter 100 of FIG. 3, the distal end 114 of cathetershaft 110 may comprise four blades 116 arranged approximately 90° apartaround the circumference of the catheter 100.

In use, the catheter 100 is inserted into the right atrium while insidesheath 150. Sheath 150 protects the surrounding vein and other tissuefrom blades 116 until the catheter 100 is in place to create theaperture. There are two broad mechanisms of action. First when catheter100 is placed against the interatrial septum tissue 30 the introducer150 may be actuated and withdrawn allowing blades 116 to open. At thispoint the catheter 100 is actuated or pushed through the interatrialseptum 30 and the blades 116 create a patterned cut in the tissue. Inthe case of four blades the pattern cut appears as an X. The four flapsof tissue that are created will provide a durable aperture.

The physician may also push the introducer 150 up against theinteratrial septum 30. The catheter 100 with the blades 116 stillretracted may be pushed through the interatrial septum 30. As it passesthrough the septum, the catheter 100 exits the introducer 150 allowingthe blades 116 to deploy. The catheter 100 is then pulled back in aproximal direction towards the right atrium cutting the tissue in thedesired pattern. As the catheter 100 is pulled back in the proximaldirection and after it has created the desired cut it will reenter thesheath 150 retracting the blades for removal from the body.

It is contemplated that a combination of the two embodiments of FIGS. 1and 3 is also possible such that a first cutting mechanism 16 willcreate a hole in the interatrial septum tissue 30 and a second cuttingmechanism 116 will create additional cuts and a flap system. The holeand the flaps together to create a durable aperture between the twoatria. Likewise, a tapered cone 60 (FIG. 3) may create a small circularhole as it passes through the septum and be followed by the bladescutting a patterned flap system. Such a device may be useful to createan elongated hole such as a slit with radiused ends. This aperturestructure may provide a low degree of shunting while the atria are at alow pressure differential and increased shunting when the atria are at ahigher pressure differential. The utility of such a design may haveparticular value with HFrEF patients. The radiusing prevents theaperture from healing over, while the nature of the slit allows fordifferent blood flow under differing pressures.

With reference to FIG. 3, the blades 116 may be extended by anycombination of a biasing arm 117, pivots 118, springs (not shown) orbiasing materials such as nitinol. In such a case the blades willtypically automatically extend when there are no restrictions on it,e.g., as the catheter exits the catheter sheath or after the catheterhas pushed through the interatrial septum to the left atrium. Inaddition it may be advantageous to have the blades automatically fold inbased on contact from one direction and automatically extend when thatcontact is removed. Thus for example the blades may extend based oncontact from a distal side e.g. as the catheter pushes into theinteratrial septum the contact with the tissue pushes a distal bladeportion 116 a in the proximal direction, causing the blade mechanism toswing out from the catheter shaft 110. The blades may then automaticallywithdraw back into the catheter as the catheter is pulled back throughthe interatrial septum and the catheter blades are contacted from theproximal side by the tissue, or vice versa. Likewise, a combination ofbiasing or contact may alternately open or close the blades. For examplethe blades may be biased to open if there are no restrictions, but maybe closed using contact with the tissue or introducer as it iswithdrawn.

Likewise the blades 116 may be extended via an actuator on a handle. Theblades 116 may be attached via pivot pins 120 to the catheter. Theblades 116 may comprise multiple blade sections 116 a and 116 b thatpivot around pivots 118, and blade sections 116 a, 116 b, may slide on aslidable pivot pin 120 a or may be secured. The blade sections 116 a,116 b may have equivalent lengths, or may be different.

Even if the blades 116 are designed so that no portion of the tissue isintentionally removed from the slits as cut, it can be desirable toemploy suction through a lumen 113 in the catheter 100 such that anytissue dislodged during the cutting process is safely removed.

While the blades 116 are illustrated with both ends attached to catheter100, it is equally possible to have only one blade end attached to thecatheter 100 and the other end effectively free or biased into positionby arm 117, a spring, or a biased construction.

While four blades are pictured, it is within the scope of thisembodiment to use other numbers of blades. In particular three blades tofive blades would provide a similar result.

Likewise, a catheter with two blades could be utilized to provide afirst cut along one axis and then be rotated 90° to provide a second cutalong a second axis. Thus after the two cuts a similar X shaped incisionin the transatrial septum would be provided. Similarly a catheter with asingle blade could be utilized to provide four cuts 90° apart each andagain provide an X shaped incision. As can be seen the desired cutpattern can be created by either providing a catheter with bladespre-existing in the desired pattern, or by providing multiple cuts withone or more blades. While embodiments above have been described withcatheter blades equidistant from each other, it is also contemplatedthat the catheter blades 116 may be arranged in a non-equidistantpattern around the catheter if in the judgment of physician a differentpattern is preferred.

Blades 116 can be provided in a number of different shapes. For examplecatheter 100 could have two diamond shaped blades (not shown) on itsdistal end. The blades can be permanently diamond shaped or could becollapsible. In the event the blades are parallel to each other and onopposite sides of the catheter the incision in the interatrial septumwill resemble an H with a hole at the middle (the hole being caused bythe catheter itself). Other shapes are also possible. For example theblades could angle towards each other at the top of the catheter andaway from each other at the bottom such that the incision in theinteratrial septum will resemble in A with a hole in the middle.

Likewise catheter 100 may include a semicircular shaped blade (notshown). In particular the catheter 100 includes a hollow lumen at itsdistal end. The cutting blade 116 comprises a semicircular shaped bladethat can be rotated. In operation the blade is rotated or extended outof the catheter. The cutting blade 116 is then rotated to cut a circularhole in the interatrial septum. The cutting blade 116 is then rotatedback into the lumen in catheter 100.

The catheter 100 may further comprise a stainless steel tube 125 with aBRK or other needle 122 on the end for piercing the interatrial septum30. The stainless steel tube 125 may be actuated manually or via anactuator on handle to pierce the interatrial septum. Once across it ispossible to use a tissue articulator such as cone 60 to increase thediameter of the hole or to work in combination with the cutting blades116 to hold the tissue in place.

In a similar embodiment, cutting blades 116 comprise a swing or supportarm at the distal end of the catheter 100. When the catheter exits asheath, or when the swing arm is actuated for release, the swing armwill rotate from being parallel to the longitudinal axis of the catheterto an orthogonal position. A razor wire is connected between theextended support arm and the body of the catheter 110 proximally of thedistal end where the swing arm is attached. As the catheter is pulledback through the tissue the razor wire will create an incision in thetissue. As can be contemplated, as above multiple cutting blades 116utilizing a razor wire are possible, and specifically four razor wiresupport arm combinations would create a similar X pattern incision intissue 30.

With reference to FIG. 3B, in a further embodiment catheter 100 ispushed through the interatrial septum 30 to the distal side. Catheter100 includes a lumen 160. Lumen 160 is closed in the distal direction asshown, but is open in the proximal direction. Nestled within lumen 160is a nitinol basket. Upon actuation the nitinol basket 170 is withdrawnproximally. In a first embodiment, as the nitinol basket 170 exits thelumen 160 it expands substantially forming a much wider basket. Theproximal edges of the basket are sharp and accordingly may be drawn intoand through the tissue both cutting the tissue to create the aperture,and retaining the tissue for removal. After the aperture is created, thecatheter is actuated a second time and the nitinol cutter 170 is pushedback into the lumen 160 causing it to close back up for removal from thebody.

In a second embodiment, as the nitinol basket 170 exits the lumen 160 itexpands substantially forming a much wider basket to serve as a tissuearticulator to retain the tissue or to hold the tissue into a cuttingmeans. As depicted, the proximal edges of the basket may be sharp andaccordingly may be drawn into the tissue to hold it and bias it into thecutting means (not shown). The basket 170 may also lack sharp edges andmay simply bias or retain the tissue, for example forming a sphericalbasket 170. After the aperture is created, the catheter is actuated asecond time and the nitinol basket 170 is pushed back into the lumen 160causing it to close back up for removal from the body.

Referring to FIG. 4, in another embodiment of the catheter 200, thecatheter 200 comprises an elongated hollow catheter shaft 210 having aninterior lumen in which one or more hooks 256 are positioned. Thecatheter 200 further comprises a distal end 220 with a lumen 222. Thehooks 256 are extended out of the catheter shaft 210 and lumen 222 andinto the tissue of the interatrial septum 30. Once the hooks 256 firmlygrasp the tissue, the hooks 256 are drawn back into lumen 222 topositively retain the tissue 30. While four hooks are shown in FIG. 4,the number of hooks may vary and in particular embodiments with one hookto four hooks are contemplated.

As shown in FIG. 4, when the tissue 30 is grasped by hooks 256 andwithdrawn into the lumen 222 the cutting device 216 may be employed tocut the aperture into the tented tissue 30. FIG. 4 depicts the hooks 256as orienting towards the center of the catheter's central axis. Howeverit is also contemplated that the hooks may be oriented away from theaxis of the catheter in another embodiment. Likewise hooks 256 are shownas a long thin rod with a short hook on the end. However, in anotherembodiment the two hooks more resemble the long grasping arms of asturdy pliers.

Tissue 30 may be grasped by hooks 256. Alternatively, tissue 30 may begrasped by one or more corkscrew elements (not shown), adhesive, abarbed insert, suction, or the like. Of course, a combination ofgrasping mechanisms may be effective.

In a further embodiment, illustrated in FIG. 5, the catheter 300comprises an elongated hollow catheter 300 having a lumen 304 in which ahooking device 306 is positioned. The catheter further comprises adistal end 320 and a blade 316. The hooking device 306 has barbs 312that are used to grab or hook into the interatrial septum. The hookingdevice 306 is used pull the septum toward the blade 316 to cut anaperture in the septum. The blade 316 may be actuated or pushed throughtissue 30 via spring 330. As with above embodiments, the hooking device306 may retract inside a cutting blade 316. However, as depicted in FIG.5, the hooking device may ride over the outside of cutting device 316,e.g., by barbs 312 riding over the outside of cutting blade 316, andcutting blade 316 sitting flush inside the barbs or the cone 306.

Hooking device 306 may include self-expanding arms 340 or portions thatmay, once the hooking device is passed through the target tissue 30 tothe distal side, expand to grab a wider portion of tissue 30. Such anarrangement allows the hooking device to begin as a smaller diameterdevice that will more easily navigate through the veins to theinteratrial septum, but then be expanded to a larger device that willattach to a larger segment of the interatrial septum to create a largeraperture. Thus, the hooking device 306 may allow the operator theability to make an aperture that is larger than the OD of the catheterdevice. Self-expanding arms 340 may comprise an additional grabbing orhooking mechanism, or may comprise a blade to provide a larger aperture.

The hooking device 306 may operate in different manners. First, it maymerely penetrate into but not through the tissue and via teeth (notshown) pull the tissue into the lumen 304 of the catheter 300.Preferably however a conically shaped hooking device 306 penetratesthrough the septum entirely, and is withdrawn back to the tissue suchthat its proximal face 350 grabs the tissue and pulls it into the lumenof the catheter 300. At this point the tissue is brought in contact withthe cutting device 316. The cutting device 316 may comprise a shapedcutting device as disclosed above. In addition cutting device 316 maycomprise a semicircular blade. The semicircular blade 316 may be rotatedsuch that as it is rotated it will create a circular hole in the tissue.The advantage of a semicircular blade over a fully circular blade isthat less force will be required for the cutting action. Thedisadvantage is that the blade must be rotated, or the entire catheterbe rotated, to create the desired cut. In the event the physician doesnot wish to remove tissue from the interatrial septum a semicircularblade may be utilized to create a flap by not rotating 360°.

While FIG. 5 shows the cutting device 316 on the distal portion of thecatheter shaft 300, the cutting device 316 may instead be on theproximal portion of hooking device 306. Likewise there may be twocutting devices 316: one on the distal end of the catheter shaft 300,and one on the proximal portion of the hooking device 306. As they aredrawn together they will cut the tissue via a scissoring action.

With reference to FIG. 6 the catheter 400 may comprise an auger 420. Theauger 420 may include a lumen 430 for riding over a guidewire 440. Inuse the guidewire 440 crosses the septum into the left atrium. The auger420 is rotated to likewise cross the septum. Because of the spiraldesign of the auger it does not create as large of a tear or perforationin the septum 30 because only one radius of the auger is in contact withthe septum at any given time. However once the auger is in the leftatrium, it may be pulled back to pull the septum 30 into cutter 416.

The cutting device may take alternative forms. Similar to thesemicircular blade, the blade may take the form of a coiled blade (notshown). The coiled blade may be contained within the lumen of thecatheter. Once deployed out of the catheter and uncoiled the blade isused to cut a hole in the septum as above. The coil may take severalforms. For instance the coiled blade may take the form of an auger (notshown). Likewise the coiled blade may take the form of a coiled rolledsheet as shown in FIG. 7. Both such forms may give the physiciandiscretion as to how large of an aperture he wishes to create in theinteratrial septum. For instance a blade formed into a coiled rolledsheet 516 may, as it exits the catheter further and further, continuallytake on a larger and larger diameter. Thus for a small aperture thephysician may only extend the coiled rolled sheet a short distance outof the catheter 500 and as such the coiled rolled sheet will only createa aperture approximately the diameter of the catheter itself. However ifa larger aperture is desired the coiled rolled sheet will be removedfurther and further out of the catheter as shown in FIG. 7 and allowedto unroll into a larger circular shape. Thus the created aperture willbe much larger. In one embodiment suction is employed with the coiledrolled sheet to hold the tissue in place.

While FIG. 7 depicts the coiled rolled sheet 516 as exiting the catheter500, it is contemplated that the coiled rolled sheet may be coiledaround the exterior of catheter 500, and may unfurl as it exits anintroducer (not shown).

Because the coiled rolled sheet is capable of creating different sizedapertures, it is possible for the physician to provide a progressiveenlargement of the aperture during the procedure. For example thephysician can create a first aperture at a first size, monitor theejection fraction for example, or the pressure in the two atria, anddetermine that a larger aperture is required. The physician would thenadapt the size of the cutting mechanism and create a second, largeraperture in the same place as the first aperture was. In thealternative, the physician could simply create a first aperture in asecond location that is substantially the same size as the firstaperture using the original size cutting means.

With reference to FIGS. 8 and 8 a, the catheter 600 may comprisemultiple angled cutting arms 616. Each cutting arm is attached to thecatheter shaft 610 by via a hinge 620. While the cutting arms 616 remainwithin the sheath 650 they are aligned with each other to present asmaller cross-section. However once deployed out of the sheath theyrotate on the hinge to form an overlapping cutting surface in a desiredshape, e.g., a circular shape as shown in FIG. 8a . While the multiplecutting arms 616 are depicted in a leaf shape that opens into the fourquarters of a circle, the cutting arms 616 may take multiple forms. Forexample while the cutting arms are depicted as being orientedperpendicularly to the longitudinal axis of catheter 600, the cuttingarms 616 may be oriented parallel to the longitudinal axis of catheter600, and as such when open would present a similar cutting edge to thecoiled rolled sheet 516 depicted in FIG. 7.

With reference to FIGS. 9A-C, a medical device assembly includes asheath 700, a catheter 710, and a guidewire 705. While the followingdescription describes the sheath 700, catheter 710 and guidewire 705 asseparate devices, it is understood that they equally can be a singledevice, be integrally connected (but preferably laterally moveablerelative to each other), and be controlled by the same or differentproximal handles and electrical connections. In particular, theattributes of the sheath 700 and catheter 710 may be advantageouslycombined. Likewise, the sheath, catheter, or guidewire may be omitted.While at least one of the devices will need to traverse the length ofthe body from the entry point to the atrium, it is contemplated that theother devices may be shorter. For example, the sheath may traverse fromthe percutaneous entry point to the right atrium. The catheter may onlytraverse from one side of the right atrium to the other, for example,and as such be substantially shorter.

Sheath 700 comprises an elongated catheter shaft 701 having a distal end702 and a proximal end (not shown). The proximal end includes a handle(not shown). The handle may comprise actuators, such as a firstactuator, a second actuator, and a third actuator (not shown). It isunderstood that in the case of multiple handle units on differentportions of the assembly, any one of the actuators discussed in thefollowing may be on different handles connected to any of the threecomponents (sheath, catheter, guidewire). The handle(s) may furtherinclude fluid port(s) and electrical connection(s) (not shown). Sheath700 and/or catheter 710 may further include pull wires attached to anactuator for actuating distal elements, moving a lumen or shaft,steering, or the like. Sheath 700 and/or catheter 710 may furtherinclude irrigation ports and the like.

Sheath 700 and/or catheter 710 further include markers 726 designed toallow the physician to determine the location and orientation of thesheath 700 and catheter 710 in the patient and the orientation of thedifferent components of the device relatively to each other. Forinstance, sheath 700 may have radiopaque markers 726 at a bend 703 in apattern that identifies the bend region. Sheath 700 may then havefurther radiopaque markers 726 at its distal end 702, again in adistinct pattern that is the same or different from the pattern at bend703. Likewise catheter 710 may have radiopaque markers 726 at its distalend. Because the catheter 710's radiopaque markers are differentlypatterned than the sheath 700's radiopaque markers, the physician willbe able to quickly and easily identify when the catheter 710 exits thesheath 700. Finally, guidewire 705 may have radiopaque markers 726 sothat the guidewire may be quickly identified by fluoroscopy as well.Preferably, the radiopaque markers 726 (or other markers) on thecatheter, sheath and guidewire are distinguishable from each other andaccordingly the physician is able to determine the spatial relationshipof the three components. In one example, spot electrodes may be used andprovide a pattern. In another example, an electroanatomical mappingsystem is programmed or provided with the specifics of the threecomponents. The specific electrodes, magnetic coils, or other electrodesare identified to the mapping system, e.g., through an EEPROM in thecatheter or otherwise, and as the system identifies a specific electrodeor coil (e.g., by the current passed through the electrode or coil andto the other components of the mapping system). The mapping system maythen clearly and visually identify the location of the three componentsfor the physician.

Advantageously, the sensors may enable the operator to create an electroanatomical map of the right atrium and left atrium. This map can includedetails such as tissue thickness, especially in the fossa ovalis or theseptum. The maps can also be created or supplemented by fluoroscopy, oran imported map such as a CT scan, MRI, live external modalities likeTTE, TEE, or information from live on-board catheter sensors, like OCT,ultrasound, CCD camera visuals, for example, to understand the surfacemorphology, tissue thicknesses, tissue compliance, location of PFO/flap,etc. These live modalities maybe also used independently. For example,the live on-board catheter sensor(s) may be an OCR sensor for imagingthe tissue to be cut. This design might also incorporate a live on-boardcatheter sensor, which is an electrode to keep cutting away from nerve,SA node artery, or for impedance tissue thickness measurements, asexamples.

Sheath 700, guidewire 705 and catheter 710 may alternatively or furtherinclude ultrasound markers (not shown) or hyper-echogenic markers, againpreferably in designed patterns as described above such that thephysician may locate the components in the patient on ultrasoundimaging. In an alternative embodiment, in place or in addition toradiopaque markers 726, the sheath 700, guidewire 705, and catheter 710may have electrodes (not shown) that are locatable on anelectroanatomical mapping system such as the EnSite™ electroanatomicalmapping system. Alternatively, the sheath 700, guidewire 705, andcatheter 710 may have magnetic coils locatable on the Carto™ orMediGuide™ mapping systems.

The elongated shaft 701 is preferably hollow, having a lumen 713 thathas the ability to pass the catheter 710 and guidewire 705 through it.The catheter 710 is designed to work in conjunction with sheath 700.Sheath 700 may either extend the entire length from the percutaneousincision to the left atrium of the heart, or may only cover a portion ofcatheter 710.

To achieve a consistent aperture of the shape desired by the physician,it is desirable that the cutting blade enter the tissue 730perpendicularly to the tissue 730. Unlike that taught in the prior artdevices, where the angle of tissue approach is not addressed, theinventors herein have found that the more squarely the cutting blade 716addresses the tissue 730, the more predictable the size of the apertureand the quality of the aperture. Accordingly, the sheath 700 and thecatheter 710 are designed to provide the operator with the ability toprovide a right angle approach to the tissue. In another embodiment, thedistal plane of the cutter is orthogonal to the plane of the tissuebeing cut. That is, the entire face of the cutting blade cuts the faceof the tissue substantially simultaneously. Because of tissueirregularity it is noted that the blade does not exactly contact thetissue simultaneously. Likewise, the blade may be a sawtoothed orFranseen blade, and may not be capable of a perfectly simultaneous cut,but rather a substantially simultaneous cut where each section of theblade cuts at the same time.

The ideal location for creating the aperture is across the thinnesttissue of the fossa, because it is the easiest to cut. However, if thefossa is crossed without controlling the angle of the crossing thecircular blade may cut a hole that is not circular and not the expectedsize. Also, a shallow angle can lead to the cutter inadvertently cuttingunintended tissues, like the atrial wall, causing a safety issue.Finally, after a device, such as a guidewire or catheter crosses theseptum, and the angle, side force, or side bias is not controlled byadjusting the angle of the device, the device can inadvertently tear orstretch the tissue. If the tear or stretch is significant enough it willimpact the resulting shape of the aperture, and in the worst case thetear will stretch into the location of the cut such that the blade isnot cutting any tissue in the location of the tear.

In one such embodiment, sheath 700 extends to the steering/bend 703. Inthis embodiment the sheath 700 may terminate before the bend 703, and assuch the medical assembly is preferably steered/bent by pull wires orbiasing in catheter 710. However, in another embodiment, the sheath 700terminates distally of bend 703. Pull wires or biasing in the sheath 700enable it to make a sufficient turn to orient catheter 710 toward theinteratrial septum 730 and thus the sheath exit and orientation providean orthogonal guide to the catheter. While in one embodiment thecatheter 710 does not have its own biasing or pull wires, in anotherembodiment the catheter 710 may be separately steerable or biased, andthus provide for the orthogonal approach. Pull wires provide theadvantage of minute adjustments to the specific anatomy of the patient,and allow for greater flexibility in the device. One device may be usedfor nearly all patients and still provide a proper approach angle.

In another embodiment the catheter is controlled b steering the distaltip with a magnetic field. Remote magnetic navigation operates by, forexample, using two large magnets placed on either side of the patient,and alterations in the magnetic field produced by the magnets deflectsthe tips of catheters within the patient to the desired direction. Thephysician operates the catheter with screen and a joystick. The catheteritself is advanced by the joystick, instead of the physician's hands.Likewise, while a physician may operate the medical devices disclosedherein by hand, the devices may be robotically driven. As with magneticnavigation, the physician operates the catheter with a screen and ajoystick. In another embodiment, providing a biasing agent such as anitinol wire to provide a preformed bend provides the advantage ofhaving a less expensive manufacturing process and a simpler device.However, multiple bend sizes may need to be manufactured.

In another embodiment, the sheath 700 may have a first preformed bend,and the catheter 710 may have a second preformed bend. The first andsecond preformed bends work together to allow the operator to direct thecutting blade 716 to the septum at a right angle. Likewise, the catheter710 may have multiple preformed bends. For example, a catheter 710 mayhave a first and second catheter preformed bend, such that for a smalleratrium only the first bend exits the sheath 700, and with the sheath'sorientation, the first bend directs the distal end of the catheter towhere the fossa ovalis typically sits for a small heart with smallerchambers. For a larger heart, however, as the catheter 710 must exitfarther out of the sheath 700 the second catheter bend also exits, andrealigns the distal end of the catheter toward where the fossa ovalistypically sits for a larger heart. Likewise, the assembly may include aremovable stiffener, that can be deployed to adjust the distal tip'slocation to provide a right angle approach to tissue 730.

The sheath 700 and the catheter 710 may include braiding to providestiffening. Unlike prior art devices which create a hole by energysources or by implanting a device, the present device may find thatsignificant pressure is necessary to create the aperture. Because thepressure must be transmitted from the length of the sheath or catheter,that pressure will initially push the cutting edge and the entirecatheter along rather than through the septum. For example, in a femoralvein entry procedure, the catheter is initially pushed upwards ratherthan towards the left atrium. Accordingly, unlike the prior art theapplicants have discovered that providing stability and steerability ineither the sheath or the catheter may greatly reduce this upwardpressure and redirect the force towards the interatrial septum 730 toprovide a proper cut.

Toward this end, sheath 700 is used to create bend 703 and direct thecatheter 710 to the septum 730. Sheath 700 terminates just distally ofthe bend 703. At this point, in one embodiment the sheath 700 is held inplace as catheter 710 is advanced out of the sheath 700 to the septum730. Because the sheath 700 is sufficiently stiff, it resists the upwardpressure and directs the catheter force toward the interatrial septum730. Together or in place of the sheath, the device contemplatesproviding anchoring means or stabilizing means (not shown) to preventthe catheter and the cutting blade from shifting and thus allowing aclean cut in the desired location. Sheath 700 and catheter 710 mayfurther include irrigation ports (not shown).

The distal end 714 of catheter 710 comprises a cutting means 716. In afirst embodiment the cutting means 716 is a razor like member formed ofsteel or another suitable metal or material adapted to cut a thintissue. Toward this end the cutting means may be very thin so that itcleanly and easily pierces the thin tissue. In those embodiments wherecutting means 716 has a sharp edge at the end of the catheter 710, it ispreferred that the sheath 700, catheter 710, proximal capture component740, or distal capture component 750 cover and protect the vein andother tissue from the cutting means 716 until the catheter 710 isdelivered in place and actuated by the physician to cut the targettissue. In other embodiments a cone (not pictured) or other distalelement may cover or sit flush with the cutting blade 716 so that theblade is protected until actuation. The cutting means may be actuated bythe advancement of a cutting means shaft (not shown) that sits within alumen of catheter 710. It may also be advanced by action of a pull wire,or via a twisting action driving a screw attached to the blade forward.

The cutter 716 in one embodiment is a shaped blade 716 located aroundthe distal catheter lumen 713. In a first embodiment, shown in FIG. 9A,shaped blade 716 is circular in shape and has on its distal end a razorlike member formed of steel or another suitable metal or material. In arelated embodiment the cutter 716 includes saw teeth for cutting throughthe tissue 730. In another embodiment cutter 716 comprises rotary blade716 and is capable of spinning or rotating to cut or form an incision.For example, if the blade is driven forward via a rotary action, thatrotary action may be accomplished by the screw mechanism above. Therotary blade 716 may comprise a blade capable of spinning in relation tothe catheter, or may comprise a distal cam action on the catheter shaft.Suction or another tissue holding mechanism is preferably employed witha rotating blade to hold the tissue in place while the cut is completed.

In other embodiments the cutter may be triangular in shape, square, oranother polygonal shape such as an octagon, such that when forcedthrough the tissue 730 the shaped blade 716 creates an aperture bycutting out an area of the tissue creating a hole, preferably a shapedhole. Notably, the shape of the hole may not match the blade precisely,e.g., an octagonal blade may create a circular hole, and tenting asdescribed herein may substantially alter the shape of the hole, e.g., acircular blade may create an oblong aperture due to uneven tenting dueto many factors, including inconsistent tissue elasticity or thickness.

As shown in FIG. 10A, cutting blade 716 may be an angled hypodermicblade. The cutting blade may have a lancet point. As only a portion cutsat any one moment, the pressure required to create the aperture isgreatly reduced. As shown in FIG. 10B, cutting blade 716 may be a sawblade (pictured) or may also be a Franseen blade. As shown in FIGS. 10Aand 10B, such blades may have a hollow lumen. When employed to cut theaperture, the lumen may be placed under a vacuum to remove any and alldebris removed from the tissue 730. The cutting means 716 may be aserrated blade which will allow for a lower cutting force. Likewise thecutting means 716 may comprise a vibrating or impulse blade to likewiseallow for a lower cutting force.

Regardless of the tissue removal or retention means, it is advantageousto include a tissue collection device. For example, the catheter mayinclude a lumen or compartment at the distal end to retain the tissue.Likewise, under suction the device may include a tissue trap, such thatfluid, blood, or other material may pass, but tissue is retained in thetrap. The physician then may monitor the trap to determine that thetissue removed from the septum has been captured, and is not still inthe heart. Such a monitoring may be automatically provided, or may bemanual by the physician. It is advantageous if such monitoring can beconducted before the catheter is removed from the patient, and as suchin one embodiment the trap is exterior to the body and readilyaccessible by the physician. In another embodiment, the trap isautomatically monitored by a sensor, such as an electrode, visualexamination, pressure sensor, or the like for the presence and volume oftissue.

Additional cutting means can include a harmonic scalpel, an RF cutter, ahigh pressure fluid jet, or a laser. The devices can cut by rotation, ahigh density ring of points, or a low density ring of point that causesperforation in the tissue that can later be separated.

In one embodiment, shown in FIG. 9A the guidewire 705 is firstpositioned across the septum 730. Guidewire 705 can pierce the septumitself using a sharp tip 706 to cut a small hole in septum 730.Alternatively a separate device, such as a BRK needle (not shown), maybe used to pierce the septum. Guidewire 705 may ride over or inside theneedle to cross through septum 730.

In one embodiment, once the sheath is in place a transeptal crossingsystem is used to cross the fossa. Then once across the crossing systemis typically replaced with a guidewire. The guidewire 705 remains inposition across the interatrial septum and guides either the sheath 700,the catheter 710, or both into position. Guidewire 705 may comprise aretention means on its distal end. In an alternative embodiment, thetranseptal crossing system is entirely separate and can cross the septumand position the guidewire before sheath 700 is inserted into the body.

Riding over the top of guidewire 705, the cutting means 716 ispositioned next to or near the interatrial septum. The cutting means 716may be so located through a physician's experience touch and feel, orusing the markers, or in conjunction with imaging system.

Once the cutting means 716 or the catheter 710 are located next to ornear the target tissue 730 the catheter 710 and/or the cutting means 716are advanced past the end of or to the end of the sheath and placed incontact with the tissue 730. Preferably using the unique markers thephysician can tell on the visualization system when the catheter hasexited the sheath 700 or has contacted the tissue. Likewise, thecatheter 710 or the cutting means 716 may include sensors (not shown)that identify when it contacts the tissue, at what angle it contacts thetissue, the thickness of the tissue, whether it is through or notthrough a PFO or a flap, if the cutting is complete, the quality of thecut edge, and the like. Such sensors can include a force sensor, fiberoptics, a camera, and electrode using impedance sensing, mappingsystems, ultrasound, or the like. In a first embodiment, the circularcutter 716 is advanced into the tissue 730 to cut a circular aperture inthe tissue. In an alternative embodiment the sheath 700 is not utilizedand the catheter 710 itself is steered into position near tissue 730,and the cutting means 716 is advanced to cut the aperture.

It is preferred that one of the first, second, or third actuators beutilized to advance the catheter 710 out of the sheath 700. It islikewise preferred that an actuator be utilized to advance cutting means716 out of catheter 710. However, either can be manually advancedwithout an actuator as well.

In another embodiment the medical device assembly includes a tissuecapture component. For example, as shown in FIG. 9A, the assembly mayinclude a distal capture component 750 designed to cross the septum tothe distal side. The distal capture component may be attached to theguidewire 705, the sheath 700, or the catheter 710. It may also beattached to a distal capture catheter 755. As such, distal capturecatheter 755 may have a lumen and ride over the guidewire 705, butinside a lumen of catheter 710. Such a lumen may be just large enough tofit over a 0.035″ guidewire. Distal capture catheter 755 may be advancedby an actuator, or have its own handle.

Once on the distal side of septum 730, the distal capture component maybe expanded as shown in FIG. 9B, and brought into contact with thetissue 730. For example, the distal capture component 750 may comprisean expandable balloon or a nitinol basket. The nitinol basket can becomprised of nitinol strands that, when released from confinement (incatheter 710, or the lumen of another element) expand into a circularcapture element. The expanded nitinol basket may be flat, e.g., orientedlargely parallel to the tissue 730, or it may be 3 dimensional, e.g.,resembling a 3 dimensional diamond shape, such that when withdrawn itprovides tissue tenting. In some embodiments the distal capturecomponent 750 may pierce and hold the tissue. In some embodiments thetissue capture component 750 is larger than the cutting blade 716. Inothers, the capture component 750 is smaller than the cutting blade 716.In still others it is substantially the same size as the cutting blade716, e.g., 6 mm.

In another embodiment the medical device assembly may include a proximalcapture component 740 designed to remain at least partially on theproximal side of the septum 730. The proximal capture component may beattached to the guidewire 705, the sheath 700, or the catheter 710. Itmay also be attached to a proximal capture catheter 745. As such,proximal capture catheter 745 may ride over the guidewire 705, butinside a lumen of catheter 710. proximal capture catheter 745 may beadvanced by an actuator, or have its own handle.

In another embodiment, shown in FIGS. 9A-C, the assembly includes bothproximal and distal tissue capture components, 740, 750. In thisembodiment the tissue capture components may be attached to the same ora different catheter or guidewire. In operation (FIG. 9B) the tissuecapture components are brought together to hold the tissue between them,both retaining the tissue in place for the cutting blade 716, and alsocapturing the tissue for removal (FIG. 9C).

FIG. 9D illustrates an exemplary device made of a distal capturecomponent 750 on the end of a distal capture component shaft 755. Thedistal capture component 750 and distal capture component shaft 755 havea lumen to accommodate guidewire 705. The proximal capture component 740is on a proximal capture component shaft 745, and both have a lumenlarge enough for the distal capture component shaft 755. The cutter 716and the cutter shaft 717 both have lumens for the proximal capturecomponent shaft 745. All three catheter shafts are assembled as shownand preferably can be advanced together or independently with respect tothe other. In use the distal capture component 750 is advanced over aguidewire 705 already across the septum and placed so the proximal edgeof this distal capture component 750 is touching the Left Atrial (LA)side of the septal tissue to be removed. Next the proximal capturecomponent 740 is advanced to the Right Atrial (RA) side of this sameseptal tissue, such that the tissue to be cut and removed is trapped orcaptured with substantial force between the distal capture component 750and the proximal capture component 740. The captured tissue then willnot stretch as the cutter is advanced. Next the cutter 716 is advancedby advancing the cutter shaft 717 until the tissue captured between thedistal capture component and proximal capture component is completelycut from surrounding tissue.

Alternatively, the cutter blade 716 and cutter blade shaft 717 can beadvanced over the guidewire and dilator into the RA prior to advancementof the capture components. In some embodiments it will be advantageousto control tissue capture forces for safety and effectiveness. In thesecases a sensor 770, and or a strain or force sensor 780 can be attachedto the capture components. In a preferred embodiment the force sensor780 is able to determine how much force is applied to the respectiveshafts, e.g., force sensor 780 determines how much force is applied tothe proximal capture component shaft 745, while force sensor 781determines how much force is applied to distal capture component shaft755. By measuring these respective forces the operator is able todetermine how firmly the tissue 730 is held between the components.Likewise, in embodiments with only one tissue capture component, theforce sensor can identify how firmly that capture component holds thetissue. In the event that the tissue is not firmly held, the operatorwill be able adjust the positioning, remove the device and reapply it,or the like. Above all, the sensors on the capture component shaft cangive the operator an indication of the safety of the operation. If thetissue is not affirmatively held, there is a risk it can break freecreating a risk of stroke due to embolization. Accordingly, knowing howwell tissue 730 is held by the tissue retention device(s) is critical.

In addition to or in the alternative to force sensors (780, 781) thedevice may comprise a sensor 770 on the proximal capture component shaft745, and sensor 771 on the capture component shaft 755. Of course,sensors 770, 771 may be located on the capture components themselves aswell. Sensors 770,771 may be used for one or more purposes, includingdetermining the location of the shafts or components, visualizing thetissue, visualizing the procedure, sensing the impedance of the tissue,sensing the proximity of another sensor or component, and the like.Examples of such sensors include magnets, electromagnetic coils,electrodes, optical strain sensors, electrical strain sensors, cameras,fiber optics, ultrasound, pressure sensors and similar sensors.Likewise, markers such as radiopaque markers or ultrasound markers maybe employed on the shafts or components.

There are three broad mechanisms for bringing the tissue capturecomponents 740, 750 together. First, the distal mechanism 750 may beactuated to move proximally into the proximal mechanism 740. Doing somay tent the tissue or bring it into a lumen on the catheter 710 or theproximal mechanism. The tissue may also be retained in a flatconfiguration (as shown). Second, the proximal mechanism 740 may beactuated to move proximally into the distal mechanism 750. Doing so maytent the tissue or bring it into a lumen on the catheter 710 or thedistal mechanism. Finally, the two tissue capture mechanisms 740, 750may be moved together, e.g., by a double bushing or double basket, tomeet at the septum 730, which in some cases may remain in place.Depending on the shape of the mechanism, the tissue may remain flat(FIG. 9b ) or may be tented (not shown).

In another embodiment, the components can be spring loaded in a way thatconsistently applies the same amount of force. For example, the movementof the tissue capture components 740, 750 and the cutting blade 716 maybe controlled from one or more handle mechanisms. With reference to FIG.11A, the handle 780 may have multiple portions 785, 790, 795 that arelinearly connected and axially movable along a central handle spindle782. In a first handle 780 (FIG. 11A) setting the tissue capturecomponents 740, 750 and the cutting blade 716 are contained within thecatheter 710. When properly positioned by the tissue 730, a firstactuation may occur. In so doing a first handle portion 785 (oractuator) is moved distally as shown in FIG. 11B. The first handle 780includes a first handle portion stop 787 that controls how far forwardthe first handle portion 785 may advance. In an alternative embodiment,there may be a stop on the tissue capture component shaft 755, on theguidewire 705, the tissue capture component shaft 745, or the catheter710 that separately controls the advancement of the first tissue capturecomponent 755. In advancing the first handle portion 785, the distaltissue capture component crosses the tissue 730 by riding over theguidewire through the hole created earlier (FIG. 9A). In one embodiment,upon actuation of actuator 788 the distal capture component 750 isexpanded (FIG. 9B).

As shown in FIGS. 11B and 11C, a second handle portion 790 is then moveddistally by the operator, which in turn moves the proximal tissuecapture component 740 in the distal direction. The first handle 780 mayinclude a stop 792 to control how far the proximal tissue capturecomponent moves, or as above a stop may be included in the distal end ofthe assembly. The handle or the distal end of the assembly may furtherinclude springs 789 or 793 to control the level of tension placed on thetwo tissue capture components. For example, spring 789 may bias thedistal tissue capture component in the proximal direction, while spring793 may bias the proximal tissue capture component in the distaldirection, providing a preset level of force to capture the tissuebetween the two devices.

Finally, when the tissue is adequately held in place, the third handleportion 795 is then moved distally by the operator, which in turn movesthe cutting edge 716 in the distal direction. The first handle 780 mayinclude a stop 797 to control how far the cutting edge 716 moves, or asabove a stop may be included in the distal end of the assembly. When theprocedure is finished, the operator may then reverse the movement of thehandle portions, such that either together or in turn each component iswithdrawn into catheter 710. Because tissue capture is critical, it isadvantageous if the first and second tissue capture components arewithdrawn together, holding the tissue in place.

Because the handle 780 controls how far the various components move,there is a greatly reduced risk of perforations in the left atrium, theprocedure is faster, and less stressful for the operator. The handle 780may further include buttons or actuators that automate the movement ofthe handle portions.

In another embodiment, once the two capture mechanisms are in place,they are preferably held in place by a closure means. For example, thetwo capture mechanisms may have respective magnets that are strongenough to hold the capture mechanisms together absent operator input.Likewise, electromagnetic force could be utilized. Alternatively, alocking mechanism may be employed, either at the capture mechanisms(such as a friction lock, or a twist lock) or at the proximal end of thecatheter, such as on a handle or actuator.

Because the distal capture component 750 must cross the septum it islikely to inflict some damage on the tissue. There can be a tradeoffbetween inflicting minimal damage to the tissue, but yet supporting thecutting action and providing sufficient capture force so the tissue issafely removed. To minimize damage to the tissue the distal capturecomponent may be made of a tapered cone as shown in FIG. 12A, a doubletapered cone as shown in FIG. 12b , an expandable metal frame like thenitinol design shown in FIG. 12c , or an expandable balloon design asshown in FIG. 12d . The distal capture component 950 may be designed sothat it has a tight fit with the cutter 916, or act as a back-stop forthe cutter 916, both facilitating the cutting action. The distal capturecomponent 950 may also be designed to hold a cutter 951 on its proximalend, as seen in FIG. 12e , such that a proximal and distal cutter act inconcert to cut the tissue. The device design may also contain a cuttermounted only to the distal capture component. The distal capturecomponent 950 may also be designed with an auger 420 (see FIG. 6) orcork screw 952 (FIG. 120 type configuration to reduce septum tissuetearing while crossing.

The proximal capture component 940 is designed to fit with the distalcapture component 950 so that it provides a high capture force of thetissue, especially at its outer circumference. Interface features ofboth of these components may be designed with high capture force,roughening surfaces or barbs (12 h), edges to the surfaces (12 g), andvacuum ports (12 i) as seen in FIGS. 12h-i . As detailed above, thecapture components may also comprise a balloon, a pigtail (not shown),an expandable nitinol basket (not shown), an disk or expandable disk(not shown) or similar means. In some embodiments a single capturemechanism can hold both proximal and distal sides of the tissue. Aballoon for example may be narrow in the middle and broad at both ends,essentially surrounding the tissue it passes through. An Auger can havesurfaces on both sides of the tissue as well, for example.

In an embodiment one or more tissue capture components will pull thetissue of the interatrial septum into a lumen 713 of catheter 710 suchthat the tissue is tented, preferably into the catheter's lumen or intoa lumen on the distal capture mechanism 750. Once the tissue is tentedthe cutter 716 will cut the tissue 730 resulting in a larger aperturedue to the tenting. Tenting the tissue has several advantages. First inmany cases it will allow for a larger aperture size combined with asmaller catheter size. Likewise it may give the physician a degree ofcontrol over the size the aperture. For example if the physician desiresa smaller aperture for a particular patient, he may wish to reduce theamount of tenting or keep it to a minimum. If the physician desires alarger aperture for the patient he will increase the amount of tentingpulling the tissue further into the lumen 713 creating a larger aperturewhen the cutting means 716 is applied.

In another embodiment the guidewire may include a tissue capturecomponent, such as a pigtail or hook. The tissue cut from theinteratrial septum to complete the aperture is positively retained bythe guidewire and pulled inside the catheter 710 when the guidewire iswithdrawn from the body and into catheter 710. While the guidewire hasbeen described as having either a balloon or pigtail, other articulationand tissue retention devices are contemplated. In particular a discdevice can be utilized. The disc device may include one disc that isnavigated to the distal side of tissue 730, or may include a disc oneach side of the tissue 730. The two discs may be actuated to secure thetissue between them. The disc may be expandable having a small diameterwhen crossing the septum and a larger diameter when securing the tissue.Cutter 716 may ride over the discs, pulling them into lumen 713, to cutthe tissue which then remains retained between the two discs and isremoved from the body.

In one embodiment the assembly may not cross the tissue 730. As shown inFIG. 13, this assembly omits the guidewire 705 and could optionally omitthe sheath 700, though in embodiments the sheath 700 still providesstability and anchoring as discussed above.

In this embodiment the distal end of catheter 710 is delivered ordirected to the tissue 730 as discussed above. A proximal tissueretention means 740 may be employed to grab the tissue from the proximalside. For example, a corkscrew device 740 may be engaged with the tissuesuch that it holds the tissue in place. Other mechanisms arecontemplated, including hooks, forceps, barbs, adhesives, and suction.For example, catheter 710 may employ one or more suction ports 735 toapply suction to the tissue 730. Suction ports 735 may be arranged onopposite sides (e.g., every 180 degrees), every 90 degrees, in a ring ofports, or in a continuous circle inside of or outside of the cuttingmechanism 716. In this embodiment the suction is employed to remove anytissue or debris that comes loose during the procedure, ensuring that noembolic material escapes.

In some embodiments ultrasound or similar can be applied to the blade toreduce the force to cut tissue. This may be especially advantageous forcutting through fibrous tissue. Also, an ultrasonic pressure reduction,or vacuum assistance, within the lumen of the cutter can be used to helppull tissue into the blade.

An energy source cutter may also reduce cutting forces. These include alaser or RF cutter with multiple emitters 716 a, b (as shown in FIG.10C) or rotating (as shown in FIG. 10D) designs. A photoselective laseror holmium laser, for example, could be used to ablate all septal tissueneeded to create the hole, so no tissue is left for removal. As shown inFIG. 14a , the distal portion of catheter 710 may consist of a patternof fiber optic cables 800. As shown in FIG. 14A, the pattern may beround, or it may be another pattern, e.g., a line, and x shape, asquare, or other. As shown in FIG. 14B, the fiber optic cables 800 maysaturate the distal portion of catheter 710.

The fiber optic cables 800 terminate at a proximal end where they areoperationally connected to a laser system, e.g., an Excimer LaserSystem, to provide laser energy for photoablation of the tissue, usinglight to break down, vaporize, or remove the tissue 730. Preferably thedistal end of the catheter 710 includes radiopaque markers 726 and avisualization system for visualizing when the tissue has been vaporized.

In one embodiment, the distal portion of the sheath 700 (or the catheter710) further comprises a suction means 820 to hold a hood 810 tightly tothe tissue 730, and over the fiber optic cables 800. In operation thesuction means 820 removes the blood from between the fiber optic cables800 and the tissue. Preferably, the embodiment includes irrigation ports830 to provide saline to replace the blood.

Similarly, the distal portion of catheter 710 may comprise an electrodedesigned to provide pulsed plasma RF energy to the tissue 730. Such anelectrode may be a unipolar or a bipolar designs, and one electrodecould be on each side of the tissue 730. In the alternative, an aperturecould be cut in tissue 730 using a design similar to FIG. 10d , but witha fluid jet as a cutter.

In another embodiment, as shown in FIG. 12A, a medical device assemblyincludes a sheath 900, a catheter 910, and a guidewire 905. While thefollowing description describes the sheath 900, catheter 910 andguidewire 905 as separate devices, it is understood that they equallycan be a single device, be integrally connected (but preferablylaterally moveable relative to each other), and be controlled by thesame or different proximal handles and electrical connections. Inparticular, the attributes of the sheath 900 and catheter 910 may beadvantageously combined. Likewise, the sheath, catheter, or guidewiremay be omitted.

Sheath 900 comprises an elongated catheter shaft 901 having a distal end902 and a proximal end (not shown). The proximal end includes a handle(not shown). The handle may comprise actuators, such as a firstactuator, a second actuator, and a third actuator. It is understood thatin the case of multiple handle units on different portions of theassembly, any one of the actuators discussed in the following may be ondifferent handles connected to any of the three components (sheath,catheter, guidewire). The handle(s) may further include a fluid port(s)and electrical connection(s) (not shown). Sheath 900 and/or catheter 910may further include pull wires attached to an actuator for actuatingdistal elements, moving a lumen or shaft, steering, or the like. Sheath900 and/or catheter 910 may further include irrigation ports and thelike.

Sheath 900, guidewire 905, and/or catheter 910 further include markers926, 928 as discussed above with respect to FIGS. 9a-d . In anotherembodiment, spot electrodes may be used and provide a pattern. Inanother embodiment, an electroanatomical mapping system is programmed orprovided with the specifics of the three components. The specificelectrodes, magnetic coils, or other electrodes are identified to themapping system, e.g., through an EEPROM in the catheter or otherwise,and as the system identifies a specific electrode or coil (e.g., by thecurrent passed through the electrode or coil and to the other componentsof the mapping system). The mapping system may then clearly and visuallyidentify the location of the three components for the physician.

Sheath 900, guidewire 905 and catheter 910 may alternatively or furtherinclude ultrasound markers (not shown) again preferably in designedpatterns as described above such that the physician may locate thecomponents in the patient on ultrasound imaging. In an alternativeembodiment, in place or in addition to radiopaque markers 926, thesheath 900, guidewire 905, and catheter 910 may have electrodes (notshown) that are locatable on an electroanatomical mapping system such asthe EnSite™ electroanatomical mapping system. Alternatively, the sheath900, guidewire 905, and catheter 910 may have magnetic coils locatableon the Carto™ or MediGuide™ mapping systems.

The elongated shaft 901 is preferably hollow, having a lumen 913 thathas the ability to pass the catheter 910 and guidewire 905 through it.The catheter 910 is designed to work in conjunction with sheath 900.Sheath 900 may either extend the entire length from the percutaneousincision to the left atrium of the heart, or may only cover a portion ofcatheter 710.

As discussed above, the sheath 900 and the catheter 910 are designed toprovide the operator with the ability to provide a right angle approachto the tissue. In one such embodiment, in the manner discussed above,sheath 900 extends to the steering/bend 903. In this embodiment thesheath 900 may terminate before the bend 903, and as such the medicalassembly is preferably steered/bent by pull wires in catheter 910.However, in another embodiment, the sheath 900 terminates distally ofbend 903. Pull wires or biasing in the sheath 900 enable it to make asufficient turn to orient catheter 910 toward the interatrial septum.While in one embodiment the catheter 910 does not have its own biasingor pull wires, in another embodiment the catheter 910 may be separatelysteerable or biased.

On the other hand, providing a biasing agent such as a nitinol wire toprovide a preformed bend provides the advantage of having a lessexpensive manufacturing process and a simpler device. However, multiplebend sizes may need to be manufactured.

In another embodiment, the sheath 900 may have a first preformed bend,and the catheter 910 may have a second preformed bend. The first andsecond preformed bends work together to allow the operator to direct thecutting blade 916 to the septum at a right angle. Likewise, the catheter910 may have multiple preformed bends. The sheath 900 and the catheter910 may include braiding to provide stiffening. Sheath 900 and catheter910 may further include irrigation ports (not shown).

The distal end of catheter 910 comprises a distal tissue capture dilator950. Distal tissue capture dilator is shown as a conical dilator, butmay take on the shape and characteristics of the dilators shown in FIGS.12A and 12 b-f. In one embodiment, distal tissue capture dilator 950comprises a cutting blade on its proximal portion. In anotherembodiment, distal tissue capture dilator 950 comprises a cutting blade952 on its distal portion for punching a hole through the tissue (FIG.15A). Distal tissue capture dilator 950 may also have a lumen 951through it for a guidewire, 905 as shown in FIG. 15B.

The distal capture component 950 may be attached to the guidewire 905,the sheath 900, or the catheter 910. It may also be attached to a distalcapture catheter 955 as shown. As such, distal capture catheter 955 mayhave a lumen and ride over the guidewire 905, but inside a lumen ofcatheter 910. Distal capture catheter 955 may be advanced by anactuator, or have its own handle.

Once on the distal side of septum, the distal capture component may beexpanded as shown in FIG. 5, and brought into contact with the tissue.In some embodiments the distal capture component 950 may pierce and holdthe tissue. In some embodiments the tissue capture component 950 islarger than the cutting blade 916, e.g., has a larger diameter. Inothers, the capture component 950 is smaller than the cutting blade 916,e.g., has a smaller diameter. In still others it is substantially thesame diameter as the cutting blade 916, e.g., 6 mm.

In another embodiment the medical device assembly may include a proximalcapture component 940 designed to remain at least partially on theproximal side of the septum. The proximal capture component may beattached to the guidewire 905, the sheath 900, or the catheter 910. Itmay also be attached to a proximal capture catheter 945. As such,proximal capture catheter 945 may ride over the guidewire 905, butinside a lumen of catheter 910. proximal capture catheter 945 may beadvanced by an actuator, or have its own handle.

In another embodiment, shown in FIG. 12, the assembly includes bothproximal and distal tissue capture components, 940, 950. In thisembodiment the tissue capture components may be attached to the same ora different catheter or guidewire. In operation the tissue capturecomponents may be at a fixed distance from each other, such that afterdistal tissue capture component 950 passes through the tissue, theelasticity of the tissue causes it to close completely or partiallyaround the distal tissue capture shaft 955. In another embodiment, thetissue capture components 940,950 are relatively slidable, and the gapbetween them is closed so that the tissue is securely held between them,both retaining the tissue in place for the cutting blade 716, and alsocapturing the tissue for removal (FIG. 9c ).

FIG. 12A illustrates an exemplary device made of a distal capturecomponent 950 on the end of a distal capture component shaft 955. Thedistal capture component 950 and distal capture component shaft 955 havea lumen to accommodate guidewire 905. The proximal capture component 940is on a proximal capture component shaft 945, and both have a lumenlarge enough for the distal capture component shaft 955. The cutter 916and the cutter shaft 917 both have lumens for the proximal capturecomponent shaft 945. All three catheter shafts are assembled as shownand preferably can be advanced together or independently with respect tothe other. In use the distal capture component 950 is advanced over aguidewire 905 already across the septum and placed so the proximal edgeof this distal capture component 750 is touching the Left Atrial (LA)side of the septal tissue to be removed. Next the proximal capturecomponent 940 is advanced to the Right Atrial (RA) side of this sameseptal tissue, such that the tissue to be cut and removed is trapped orcaptured with substantial force between the distal capture component 950and the proximal capture component 740. The captured tissue then willnot stretch as the cutter is advanced. Next the cutter 916 is advancedby advancing the cutter shaft 917 until the tissue captured between thedistal capture component and proximal capture component is completelycut from surrounding tissue. In an alternative embodiment, cutting edge960 and cutter 916 operate together with a scissor action to cut thetissue. In another embodiment, cutter 916 is absent and cutting edge 960cuts the tissue.

In a first embodiment the cutting means 916 is a razor like memberformed of steel or another suitable metal or material adapted to cut athin tissue. Cutting means 916 can take any form discussed herein,including the forms disclosed in FIGS. 10A-D, a shaped blade, a sawblade, a rotary blade or the like.

Once the cutting means 916 or the catheter 910 are located next to ornear the target tissue the catheter 910 and/or the cutting means 916 areadvanced past the end of or to the end of the sheath and placed incontact with the tissue. Preferably using the unique markers thephysician can tell on the visualization system when the catheter hasexited the sheath 900 or has contacted the tissue. Likewise, thecatheter 910, the dilator 950, the proximal tissue capture component740, their respective catheter shafts, and the cutting means 916 mayinclude sensors (not shown) that identify when it contacts the tissue,such as a force sensor, fiber optics, a camera, and electrode usingimpedance sensing, mapping systems, ultrasound, or the like. In a firstembodiment, the circular cutter 916 is advanced into the tissue to cut acircular aperture in the tissue. In an alternative embodiment the sheath900 is not utilized and the catheter 910 itself is steered into positionnear tissue, and the cutting means 916 is advanced to cut the aperture.

It is preferred that one of the first, second, or third actuators beutilized to advance the catheter 910 out of the sheath 900. It islikewise preferred that an actuator be utilized to advance cutting means916 out of catheter 910. However, the catheter 910 can be manuallyadvanced without an actuator as well.

In some embodiments it will be advantageous to control tissue captureforces for safety and effectiveness. In these cases a sensor 970, and ora strain or force sensor can be attached to the capture components. In apreferred embodiment the force sensor 970 is able to determine how muchforce is applied to the respective shafts, e.g., one or more forcesensor(s) 970 determines how much force is applied to the proximalcapture component shaft 945, while another force sensor determines howmuch force is applied to distal capture component shaft. By measuringthese respective forces the operator is able to determine how firmly thetissue is held between the components. Likewise, in embodiments withonly one tissue capture component, the force sensor can identify howfirmly that capture component holds the tissue.

Sensors may be used for one or more purposes, including determining thelocation of the shafts or components, visualizing the tissue,visualizing the procedure, sensing the impedance of the tissue, sensingthe proximity of another sensor or component, and the like. Examples ofsuch sensors include magnets, electromagnetic coils, electrodes, opticalstrain sensors, electrical strain sensors, cameras, fiber optics,ultrasound, and similar sensors. Likewise, markers such as radiopaquemarkers or ultrasound markers may be employed on the shafts orcomponents.

There are three broad mechanisms for bringing the tissue capturecomponents 940, 950 together, as discussed above and incorporated here.In another embodiment, the components can be spring loaded in a way thatconsistently applies the same amount of force, as also discussed abovein connection with FIGS. 11a-c . Because the handle controls how far thevarious components move, there is a greatly reduced risk of perforationsin the left atrium, the procedure is faster, and less stressful for theoperator. In another embodiment, once the two capture mechanisms are inplace, they are preferably held in place by a closure means. Forexample, the two capture mechanisms may have respective magnets that arestrong enough to hold the capture mechanisms together absent operatorinput. Likewise, electromagnetic force could be utilized. Alternatively,a locking mechanism may be employed, either at the capture mechanisms(such as a friction lock, or a twist lock) or at the proximal end of thecatheter, such as on a handle or actuator.

Because the distal capture component 950 must cross the septum it islikely to inflict some damage on the tissue. There can be a tradeoffbetween inflicting minimal damage to the tissue, but yet supporting thecutting action and providing sufficient capture force so the tissue issafely removed. To minimize damage to the tissue the distal capturecomponent may be made of a tapered cone as shown in FIG. 12A, a doubletapered cone as shown in FIG. 12b , an expandable metal frame like thenitinol design shown in FIG. 12c , or an expandable balloon design asshown in FIG. 12d . The distal capture component 1 may be designed sothat it has a tight fit with the cutter 916, or act as a back-stop forthe cutter 916, both facilitating the cutting action. The distal capturecomponent 950 may also be designed to hold a cutter 951 on its proximalend, as seen in FIG. 12e , such that a proximal and distal cutter act inconcert to cut the tissue. The device design may also contain a cuttermounted only to the distal capture component. The distal capturecomponent 950 may also be designed with an auger 420 (see FIG. 6) orcork screw (FIG. 12f ) type configuration to reduce septum tissuetearing while crossing.

In the embodiment shown in FIG. 12A, the proximal capture component 940is designed to fit with the distal capture component 950 so that itprovides a high capture force of the tissue, especially at its outercircumference. Interface features of both of these components may bedesigned with high capture force, roughening surfaces or barbs (12 h),edges to the surfaces (12 g), and vacuum ports (12 i) as seen in FIGS.12h-i . As detailed above, the capture components may also comprise aballoon, a pigtail (not shown), an expandable nitinol basket (notshown), an disk or expandable disk (not shown) or similar means. In someembodiments a single capture mechanism can hold both proximal and distalsides of the tissue. A balloon for example may be narrow in the middleand broad at both ends, essentially surrounding the tissue it passesthrough. An Auger can have surfaces on both sides of the tissue as well,for example.

In an embodiment one or more tissue capture components will pull thetissue of the interatrial septum into a lumen 913 of catheter 910 suchthat the tissue is tented, preferably into the catheter's lumen or intoa lumen on the distal capture mechanism 950. Once the tissue is tentedthe cutter 916 will cut the tissue resulting in a larger aperture due tothe tenting. Tenting the tissue has several advantages. First in manycases it will allow for a larger aperture size combined with a smallercatheter size. Likewise it may give the physician a degree of controlover the size the aperture. For example if the physician desires asmaller aperture for a particular patient, he may wish to reduce theamount of tenting or keep it to a minimum. If the physician desires alarger aperture for the patient he will increase the amount of tentingpulling the tissue further into the lumen 913 creating a larger aperturewhen the cutting means 916 is applied.

In another embodiment, shown in FIGS. 16a-c , a medical device assemblyincludes a sheath 1000 that comprises an elongated catheter shaft 1001having a distal end 1002 and a proximal end (not shown). The proximalend includes a handle (not shown). The handle may comprise actuators,such as a first actuator, a second actuator, and a third actuator. It isunderstood that in the case of multiple handle units on differentportions of the assembly, any one of the actuators discussed in thefollowing may be on different handles connected to any of the threecomponents (sheath, catheter, guidewire). Likewise, one or more elementsmay not have a handle, such as the guidewire. The handle(s) may furtherinclude a fluid port(s) and electrical connection(s) (not shown). Sheath1000 may include an inner catheter 1010 may further include pull wiresattached to an actuator for actuating distal elements, moving a lumen orshaft, steering, or the like. Sheath 1000 and/or catheter 1010 mayfurther include irrigation ports and the like. While a guidewire is notpictured, and in one embodiment is not used, in another embodiment aguidewire (not shown) may be used to guide the catheter to the tissue.

Sheath 1000, and/or catheter 1010 further include markers 1026 asdiscussed above with respect to FIGS. 9a-d . In another embodiment, spotor ring electrodes may be used and provide a pattern. In anotherembodiment, an electroanatomical mapping system is programmed orprovided with the specifics of the three components. The specificelectrodes, magnetic coils, or other electrodes are identified to themapping system, e.g., through an EEPROM in the catheter or otherwise,and as the system identifies a specific electrode or coil (e.g., by thecurrent passed through the electrode or coil and to the other componentsof the mapping system). The mapping system may then clearly and visuallyidentify the location of the three components for the physician.

Sheath 1000 and catheter 1010 may alternatively or further includeultrasound markers (not shown) again preferably in designed patterns asdescribed above such that the physician may locate the components in thepatient on ultrasound imaging. In an alternative embodiment, in place orin addition to radiopaque markers 1026, the sheath 1000, and catheter1010 may have electrodes (not shown) that are locatable on anelectroanatomical mapping system such as the EnSite™ electroanatomicalmapping system. Alternatively, the sheath 1000 and catheter 1010 mayhave magnetic coils locatable on the Carto™ or MediGuide™ mappingsystems.

The elongated shaft 1001 is preferably hollow, having a lumen that hasthe ability to pass the catheter 1010 through it. The catheter 1010 isdesigned to work in conjunction with sheath 1000. Sheath 1000 may eitherextend the entire length from the percutaneous incision to the leftatrium of the heart, or may only cover a portion of catheter 1010.

To achieve a consistent aperture of the shape desired by the physician,it is desirable that the cutting blade enter the tissue 1030 (FIG. 16b )perpendicularly to the tissue 1030. Unlike that taught in the prior artdevices, where the angle of tissue approach is not addressed, theinventors herein have found that the more squarely the cutting blade1016 or blades 1016 a, b, addresses the tissue 1030, the morepredictable the size of the aperture and the quality of the aperture. Inaddition, the cut is safer as the blade is less likely to encounterunintended tissue on the septum or the atrial wall. Accordingly, thesheath 1000 and the catheter 1010 are designed to provide the operatorwith the ability to provide a right angle approach to the tissue.

In one such embodiment, sheath 1000 extends to a bend (not shown). Inthis embodiment the sheath 1000 may terminate before the bend, and assuch the medical assembly is preferably steered/bent by one or more pullwires or fibers in catheter 1010, or by a push wire, preshaped rod, orsimilar means. However, in another embodiment, the sheath 1000terminates distally of the bend.

In one particular embodiment depicted in FIGS. 16a-c , it is especiallyadvantageous for the sheath 1000 to travel to the tissue 1030 as theactuation of the cutting mechanism 1016 may be controlled by movement ofthe sheath.

Pull wires or biasing in the sheath 1000 enable it to make a sufficientturn to orient catheter 1010 toward the interatrial septum. While in oneembodiment the catheter 1010 does not have its own biasing or pullwires, in another embodiment the catheter 1010 may be separatelysteerable or biased.

On the other hand, providing a biasing agent such as a nitinol wire toprovide a preformed bend provides the advantage of having a lessexpensive manufacturing process and a simpler device. However, multiplebend sizes may need to be manufactured.

In another embodiment, the sheath 1000 may have a first preformed bend,and the catheter 1010 may have a second preformed bend. The first andsecond preformed bends work together to allow the operator to direct thecutting blade 1016 to the septum at a right angle. Likewise, thecatheter 1010 may have multiple preformed bends. The sheath 1000 and thecatheter 1010 may include braiding to provide stiffening. Sheath 1000and catheter 1010 may further include irrigation ports (not shown).Together or in place of the sheath, the device contemplates providinganchoring means or stabilizing means (not shown) to prevent the catheterand the cutting blade from shifting and thus allowing a clean cut in thedesired location.

In a first embodiment the cutting means 1016 is a razor like memberformed of steel or another suitable metal or material adapted to cut athin tissue. Cutting means 1016 can take any form discussed herein,including the forms disclosed in FIGS. 10A-D, a shaped blade, a sawblade, a rotary blade or the like.

In another embodiment, the cutting means 1016 comprises twin blades 1016a,b. Cutting blades 1016 a,b are connected to catheter 1010 by flexiblemembers 1017 a,b. For example, flexible members 1017 a,b could be a leafspring. Preferably the flexible members 1017 a,b bias the cutting blades1016 a,b toward the central axis of catheter 1010. The distal most andradially inner most edge of the cutting blades 1016 a,b are sharpenedfor cutting tissue. Cutting blades 1016 a,b may include additionalcutting features, such as teeth, vibration, rotation and the like, asdiscussed above. Additionally, while two cutting blades are pictured,other numbers are contemplated, particularly 1, 3, and 4 blades. Thecutter could have a collet design instead of cutters, or a circularblade.

While the sheath 1000 assembly navigates through the body to thesurgical site, the flexible members 1017 a,b, and the cutting blades1016 a,b are folded into the lumen 1020 of the catheter 1010. As suchthey do not present an impediment to the motion of the catheter throughthe vasculature. When the catheter is properly positioned at the tissue1030, the proximal tissue capture mechanism 1040 is advanced forward, asdiscussed above. Originally located behind cutting blades 1016 a,b, thetissue capture mechanism was fully out of the way of these blades, andaccordingly they were folded into the lumen 1020 of the catheter 1010.However, when it is moved distally, proximal tissue capture mechanismforces the blades 1016 a,b radially outward. For example, blade 1016 ais forced radially outward through cutout 1080.

Tissue capture mechanism 1040 may comprise any tissue capture mechanismdiscussed herein. In one embodiment the blades 1016 are the tissuecapture mechanism in that they are adapted to grab the tissue to be cut.It can be advantageous to have a locking mechanism to hold the blades1016 a, b, in locked and closed state once the tissue has been cut sothat the blades 1016 would also function as a tissue removal mechanism.For example, a handle may have an actuator for moving the blades, andthis actuator may include a lock to lock the blades in place so thatthey may not be inadvertently opened to release the tissue.

In a preferred embodiment, tissue capture mechanism 1040 comprises alumen 1070 that conveys suction to the tissue 1030. When the operatoridentifies that the distal end of the assembly is in contact with thedesired portion of the tissue (and preferably at a right angle thereto),the suction may be activated. The tissue 1030 is pulled into the lumen1020. At this point, in one embodiment the tissue capture mechanism iswithdrawn proximally pulling the tissue into the lumen (and tenting thetissue, allowing an increased aperture size). As the proximal tissuecapture mechanism passes the blades 1016 a,b, it releases them from theradially outward position. They will close on, and cut the tissue 1030,leaving an aperture in tissue 1030 (FIG. 16d ).

In an alternative embodiment, when the tissue is in place and subject tosuction, the operator pulls back on the shaft. The blades at this pointopen as they are biased or normally open and are only held in place bythe shaft during insertion to the body. Once the shaft is pulled backthe tissue is then pulled into the blades with the suction. Once thetissue is inside the blades the shaft is advanced to close the blades,cutting the tissue as well as retaining it. In the alternative, thesuction may not be applied prior to shaft pullback, but may first beapplied after the blades are open.

In this embodiment the distal end of shaft 1080 is advanced to close theblades as the shaft slides distally, cutting the tissue. The shaft thenremains forward, either locked in position or held in position byfriction or the doctor, such that the tissue is captured and cannot beaccidentally released.

While FIG. 16b depicts a central lumen to provide the suction, inanother embodiment multiple lumens—for example in a roughly circularpattern—grab the tissue.

While in the above embodiment the tissue is retained with suction, othertissue capture mechanisms are contemplated, such as a forceps, a barb,an auger, hooks, a corkscrew. Of course, multiple tissue retention meansmay be utilized, such as suction with an auger to hold a locationsteady, hooks, a corkscrew, or the like. The initial capture may beadditionally secured with additional grasping jaws, a collet, or similarmeans.

Preferably using unique markers or sensors on the different componentsof this assembly, the physician can tell on a visualization system whenthe blades have exited the sheath, the tissue retention mechanism hascontacted the tissue, the mechanism has withdrawn into the catheter withthe tissue, and the blades have closed cutting the tissue. Likewise, theassembly components may include sensors (not shown) that identify whenthey contacts the tissue, such as a force sensor, fiber optics, acamera, and electrode using impedance sensing, mapping systems,ultrasound, or the like. In another embodiment the blades haverespective sensors that identify when they have contacted the tissueretention mechanism, and when they have contacted each other completinga cut.

While the sheath 1000 and catheter 1010 assembly is straightforward tooperate without handles and actuators, in one embodiment one or morehandles have one or more actuators to control the steering of theassembly, the advancement of the proximal tissue capture mechanism, orthe operation of the blades. For example, the blades may remain in anopen position even after the tissue capture mechanism 1040 passesproximally, and only close upon actuation by the operator. The actuationmay provide additional force to increase the cutting mechanism'seffectiveness. Likewise, the cutting mechanism may be assisted by amutual attraction (e.g., magnetic or electromagnetic) or repulsion.Additionally, the actuation can be utilized to help control the size ofthe aperture, in that the farther the tissue is drawn into the lumen,the larger the aperture will be. Once closed, the cutting mechanism mayhelp retain the tissue in the catheter.

Because this embodiment need not cross the septum and can remainentirely in the right atrial side, the procedure is simpler, faster, anddoes not need as many expensive medical devices. In addition, as theprocedure is entirely in the right atrium, irrigation is not required toavoid thrombus in the catheter. The absence of a perforating needleeliminates the risk of a perforation to the left atrial wall. It alsohas the advantage that it can readily provide a second aperture, as thetissue from the first aperture will not interfere with the action of thedevice.

Once a hole is created in the septal wall there are two ways to increasethe area of removed tissue. The first is to simply create another hole.The second way to increase the area of removed tissue in the wall is toenlarge a present hole. To enlarge an existing hole the cutter 716,which may be a blade, energy source or the like as described above, ispreferably aligned in the plane of the septum 730 as in FIG. 17a . Thenthe cutter 716 must be moved within the plane of the septum 730 toengage the septal tissue edge, 731 as shown in FIG. 17b . A tissuecookie can be cut and removed, or the laser or RF vaporizingtechnologies can be used to vaporize all the additional tissue meant forremoval. The movements, cutter, and tissue to be cut will be relativelysmall compared to common imaging capabilities, and the imagingcapability may only be 2D. Accordingly, the catheter 710 includessensors 780 such an impedance, ultra sound, OCR, etc. to localize thetissue to be cut with respect to the cutter. The sensor 780 couldalternatively be a suction port or orifice (a hole). The sensor(s) canbe on the device, in the cutter element, or anywhere in the cuttingregion. In one embodiment the same optical fiber used for laser cuttingcan also be used for tissue sensing, or the same RF electrodes used fortissue cutting can be used to sense the orientation of tissue within thecutter region.

In the suction case if a low pressure can be pulled on the orifice itmay be expected that it is blocked by tissue and tissue is ready to cut.Likewise, a biopsy type forceps with sensing capability is used toincrease hole diameter by grabbing a portion of tissue for the cutter tocut. To facilitate controlled catheter movements a catheter handle canbe locked in place with respect to the septal wall, e.g., by fasteningthe handle, the sheath, or the catheter to the patient's bedside.

Regardless of the tissue removal or retention means, it is especiallyadvantageous to include a tissue collection device when attempting asecond cut. For example, the catheter may include a lumen or compartmentat the distal end to retain the tissue. Likewise, under suction thedevice may include a tissue trap, such that fluid, blood, or othermaterial may pass, but tissue is retained in the trap. The physicianthen may monitor the trap to determine that the tissue removed from theseptum has been captured, and is not still in the heart. Such amonitoring may be automatically provided, or may be manual by thephysician. It is advantageous if such monitoring can be conducted beforethe catheter is removed from the patient, and as such in one embodimentthe trap is exterior to the body and readily accessible by thephysician. In another embodiment, the trap is automatically monitored bya sensor, such as an electrode, visual examination, pressure sensor, orthe like for the presence and volume of tissue.

Typically the device types described herein work best if there is nobias, or force on the tissue in any direction other than what isnecessary to capture and cut. The exception is a device used to increasean existing holes size, in which case biasing the shaft and cutter intothe side of the previous hole is necessary. In general though, if thereis bias in or out of the septal plane during capture for instance, thetissue will likely be stretched over the capture components prior tocapture, making the resulting hole smaller than expected. Likewise, ifthe bias is within the septal plane prior to capture, the device shaftwill elongate or tear the hole such that the capture has minimal tissueon one side and bunched tissue on the other. If a cut is made in thelatter situation, the cutter may pass through, on one side, the holecreated by the bias, leaving an elongated hole. Also, if part of the cutpasses through a hole stretched by bias, the tissue around the shaftwill not be complete, creating an increased safety risk that would needmitigating.

To remove bias—device stability, control and feedback is needed.Stability can be achieved at least three ways. First, a distal structure1170 as in FIG. 18, attached to the outer sheath can engage the septaltissue, allowing all adjustments to be with respect to it. This framestructure may be at least partly disconnected from the proximalcomponents to minimize unintended forces. The frame structure mayconsist of one or more struts extending from the catheter or sheath,designed to lean against the tissue and hold the catheter and cutterorthogonally to the tissue. Likewise, in another embodiment thestructure may be a hood. A hood structure would also allow a suction toremove all blood and provide direct visualization of the septum. Inanother example the distal structure 1170 may be a balloon on the outersurface of the sheath, such that when inflated the balloon structurematches the contour of the septum and provides for an orthogonal guideto the sheath, catheter, or blade. In each case, the orthogonal guide ispreferably collapsible for delivery into the atrium.

Second, the device, such as the sheath or catheter shaft, can be affixedsecurely to the patients puncture site via a catheter holder, allowingall adjustments to be with respect to the puncture site and thereforethe septum. Finally, the catheter handle can be affixed to the patient,drape, bed rail mount/platform, or similar via a catheter holder.

A catheter holder would secure either the catheter shaft, catheterhandle, or both. The combination of the catheter handle and catheterholder would secure and hold constant the catheter shaft, and thereforehold constant the distal end of the catheter tip, from rotation,bending, longitudinal movements, alignment, bias, tissue captureactuation and cutter operation. The operator could then control fineadjustable movements of the handle or catheter holder in order to makefine prescribed movements to the catheter distal tip, for moreaccurately and safely cutting a hole in the interatrial septum.

Since each of these progressively is further from the septum, theyprogressively become less stable. However, each is more stable than theclinician simply controlling localization with his hand. Control of thedistal tip of the devices is achieved through the device rotation, shaftdeflection, bending of the shaft, and actuation of the distalcomponents. In some cases, for precise aperture creation, these criticalcontrol movements may be less than 1 mm, making the previously mentioneddevice stability critical. As input into the decision to manipulate thecontrols for proper aperture creation precise feedback is necessary.Feedback described above included, bias force sensing, tissue thicknesssensing, device localization sensing, visual handle controls of distalcatheter elements, as examples. Most of the control and feedback are inreference to some stable device reference point established somewherealong the catheter, as necessary to deliver a precise aperture quicklyand safely.

In another embodiment, the cutting means is allowed to “float” withrespect to the catheter, such that it is contact with the tissue thatgoverns the orientation of the cutting means, rather than theorientation of the catheter. In particular, if the bottom side of acircular cutter contacts the tissue first, the cutter will pivot as itspushed forward, for example, so that only the top portion moves forwarduntil the entire cutter is substantially in contact with the tissue. Forexample, in one embodiment the cutter may be attached to the medicaldevice via a central shaft, and spaced from the catheter via springsaround the periphery, such that under light pressure from the fossa, thecutter compresses one or more springs, but does not initially compressthe others, causing the cutter face to move into an orthogonal positionvis a vis the tissue. As the cutter comes fully into contact with thetissue, the pressure from the catheter continues to rise and it ispushed orthogonally through the tissue.

1. A medical device assembly comprising: a sheath, the sheathcomprising: an elongated sheath shaft, the sheath shaft having a firstbend region, a central lumen and a distal end, a first steering wire,the steering wire having a first position and a second position, whereinat the first position the first bend region is substantially linear, andwherein at the second position the distal end of the sheath issubstantially perpendicular to a longitudinal axis of the sheath, acatheter inside the sheath, the catheter comprising: a catheter shaft,the catheter shaft having a central lumen, a shaped blade, the shapedblade comprising: a blade cutting edge that is oriented at asubstantially right angle to the longitudinal axis of the sheath whenthe sheath is oriented substantially perpendicular to the inter atrialseptum, and is adapted to cut a 3 mm or larger durable aperture in theinteratrial septum, a tissue articulator adapted to hold the interatrialseptum.
 2. The assembly of claim 1 further comprising a marker toidentify the catheter location on a visualization system.
 3. Theassembly of claim 1, wherein the articulator is a suction device.
 4. Theassembly of claim 3, wherein the assembly does not comprise a componentadapted to cross the interatrial septum such as a guidewire or needle.5. The assembly of claim 3, wherein the articulator is adapted to retainthe interatrial septum from only the same side of the interatrial septumas the shaped blade cuts the interatrial septum.
 6. The assembly ofclaim 1 wherein the shaped blade is selected from the group consistingof a circular blade, a square blade, a triangular blade, a sawtoothedblade, a franseen blade, or a polygonal blade.
 7. The assembly of claim1 further comprising a tissue removal device.
 8. The assembly of claim 1wherein the articulator comprises a tissue removal device.
 9. Theassembly of claim 7 wherein the tissue removal device is adapted toremove or hold a first tissue portion so that the articulator can hold asecond tissue portion against the blade.
 10. The assembly of claim 9wherein the tissue removal device is a suction mechanism adapted toremove the first tissue portion.
 11. The assembly of claim 1 furthercomprising an anchor.
 12. The assembly of claim 11 wherein the anchorattaches to the interatrial septum.
 13. The assembly of claim 11 whereinthe anchor attaches to one of the patient's exterior or the patient'sbedside.
 14. The assembly of claim 1 further comprising an orthogonalguide, the orthogonal guide adapted to hold the shaped blade in anorthogonal position to the interatrial septum.
 15. The assembly of claim1, further comprising an actuator operably connected to the tissuearticulator, and wherein the tissue articulator has a first setting anda second setting, the tissue articulator being adapted to hold theinteratrial septum against the shaped blade for cutting while in thesecond setting, and wherein the actuator has a first position and asecond position, wherein when the actuator is in the second position thetissue articulator holds the interatrial septum against the shapedblade.
 16. A medical device assembly comprising: a sheath, the sheathcomprising: an elongated sheath shaft, the sheath shaft having a firstbend region, a central lumen and a distal end, a first steering wire,the steering wire having a first position and a second position, whereinat the first position the first bend region is substantially linear, andwherein at the second position the distal end of the sheath issubstantially perpendicular to a longitudinal axis of the sheath, acatheter inside the sheath, the catheter comprising: a catheter shaft, ashaped blade, the shaped blade comprising: a blade cutting edge that isoriented at a substantially right angle to the longitudinal axis of thesheath when the sheath is oriented substantially perpendicular to theinter atrial septum, and is adapted to cut a 3 mm or larger durableaperture in the interatrial septum, a tissue articulator, the tissuearticulator having a first setting and a second setting, the tissuearticulator being adapted to hold the interatrial septum against theshaped blade for cutting while in the second setting, an actuatorconnected to the tissue articulator, the actuator having a firstposition and a second position, wherein when the actuator is in thesecond position the tissue articulator holds the interatrial septumagainst the shaped blade.
 17. The assembly of claim 16 furthercomprising a suction opening configured to provide suction in theapproximate area of the shaped blade.
 18. The assembly of claim 16wherein the tissue articulator is a tapered cone having a proximal face,the proximal face being adapted to retain a tissue.
 19. A method oftreating a heart comprising the steps of: inserting a catheter into theright atrium of the heart, the catheter comprising: a shaft, a distalcatheter lumen, a shaped cutting blade arranged around the distalcatheter lumen, a tissue articulator, the tissue articulator having afirst position and a second position, an actuator connected to thetissue articulator a steering mechanism while the catheter is in theright atrium, actuating the actuator to move the tissue articulator intoa second position that holds the tissue against the shaped cuttingblade, cutting an aperture in the interatrial septum between the rightatrium and the left atrium, removing a cut tissue from the right atrium.20. The method of claim 19 further comprising a step of attaching atissue removal device to a portion of the interatrial septum.